Abstract libuv implementation

Structures the libuv implementation to allow for a plugable
BSD style socket implementation to allow for other IO Managers

Author: kpayson64

BUILD

@@ -713,20 +713,25 @@ grpc_cc_library(
         "src/core/lib/iomgr/gethostname_sysconf.cc",
         "src/core/lib/iomgr/iocp_windows.cc",
         "src/core/lib/iomgr/iomgr.cc",
+        "src/core/lib/iomgr/iomgr_custom.cc",
+        "src/core/lib/iomgr/iomgr_internal.cc",
         "src/core/lib/iomgr/iomgr_posix.cc",
-        "src/core/lib/iomgr/iomgr_uv.cc",
         "src/core/lib/iomgr/iomgr_windows.cc",
         "src/core/lib/iomgr/is_epollexclusive_available.cc",
         "src/core/lib/iomgr/load_file.cc",
         "src/core/lib/iomgr/lockfree_event.cc",
         "src/core/lib/iomgr/network_status_tracker.cc",
         "src/core/lib/iomgr/polling_entity.cc",
-        "src/core/lib/iomgr/pollset_set_uv.cc",
+        "src/core/lib/iomgr/pollset.cc",
+        "src/core/lib/iomgr/pollset_custom.cc",
+        "src/core/lib/iomgr/pollset_set.cc",
+        "src/core/lib/iomgr/pollset_set_custom.cc",
         "src/core/lib/iomgr/pollset_set_windows.cc",
         "src/core/lib/iomgr/pollset_uv.cc",
         "src/core/lib/iomgr/pollset_windows.cc",
+        "src/core/lib/iomgr/resolve_address.cc",
+        "src/core/lib/iomgr/resolve_address_custom.cc",
         "src/core/lib/iomgr/resolve_address_posix.cc",
-        "src/core/lib/iomgr/resolve_address_uv.cc",
         "src/core/lib/iomgr/resolve_address_windows.cc",
         "src/core/lib/iomgr/resource_quota.cc",
         "src/core/lib/iomgr/sockaddr_utils.cc",
@@ -735,22 +740,26 @@ grpc_cc_library(
         "src/core/lib/iomgr/socket_utils_common_posix.cc",
         "src/core/lib/iomgr/socket_utils_linux.cc",
         "src/core/lib/iomgr/socket_utils_posix.cc",
-        "src/core/lib/iomgr/socket_utils_uv.cc",
         "src/core/lib/iomgr/socket_utils_windows.cc",
         "src/core/lib/iomgr/socket_windows.cc",
+        "src/core/lib/iomgr/tcp_client.cc",
+        "src/core/lib/iomgr/tcp_client_custom.cc",
         "src/core/lib/iomgr/tcp_client_posix.cc",
-        "src/core/lib/iomgr/tcp_client_uv.cc",
         "src/core/lib/iomgr/tcp_client_windows.cc",
+        "src/core/lib/iomgr/tcp_custom.cc",
         "src/core/lib/iomgr/tcp_posix.cc",
+        "src/core/lib/iomgr/tcp_server.cc",
+        "src/core/lib/iomgr/tcp_server_custom.cc",
         "src/core/lib/iomgr/tcp_server_posix.cc",
         "src/core/lib/iomgr/tcp_server_utils_posix_common.cc",
         "src/core/lib/iomgr/tcp_server_utils_posix_ifaddrs.cc",
         "src/core/lib/iomgr/tcp_server_utils_posix_noifaddrs.cc",
-        "src/core/lib/iomgr/tcp_server_uv.cc",
         "src/core/lib/iomgr/tcp_server_windows.cc",
         "src/core/lib/iomgr/tcp_uv.cc",
         "src/core/lib/iomgr/tcp_windows.cc",
         "src/core/lib/iomgr/time_averaged_stats.cc",
+        "src/core/lib/iomgr/timer.cc",
+        "src/core/lib/iomgr/timer_custom.cc",
         "src/core/lib/iomgr/timer_generic.cc",
         "src/core/lib/iomgr/timer_heap.cc",
         "src/core/lib/iomgr/timer_manager.cc",
@@ -845,24 +854,28 @@ grpc_cc_library(
         "src/core/lib/iomgr/gethostname.h",
         "src/core/lib/iomgr/iocp_windows.h",
         "src/core/lib/iomgr/iomgr.h",
+        "src/core/lib/iomgr/iomgr_custom.h",
         "src/core/lib/iomgr/iomgr_internal.h",
         "src/core/lib/iomgr/iomgr_posix.h",
-        "src/core/lib/iomgr/iomgr_uv.h",
         "src/core/lib/iomgr/is_epollexclusive_available.h",
         "src/core/lib/iomgr/load_file.h",
         "src/core/lib/iomgr/lockfree_event.h",
         "src/core/lib/iomgr/nameser.h",
         "src/core/lib/iomgr/network_status_tracker.h",
         "src/core/lib/iomgr/polling_entity.h",
         "src/core/lib/iomgr/pollset.h",
+        "src/core/lib/iomgr/pollset_custom.h",
         "src/core/lib/iomgr/pollset_set.h",
+        "src/core/lib/iomgr/pollset_set_custom.h",
         "src/core/lib/iomgr/pollset_set_windows.h",
         "src/core/lib/iomgr/pollset_uv.h",
         "src/core/lib/iomgr/pollset_windows.h",
         "src/core/lib/iomgr/port.h",
         "src/core/lib/iomgr/resolve_address.h",
+        "src/core/lib/iomgr/resolve_address_custom.h",
         "src/core/lib/iomgr/resource_quota.h",
         "src/core/lib/iomgr/sockaddr.h",
+        "src/core/lib/iomgr/sockaddr_custom.h",
         "src/core/lib/iomgr/sockaddr_posix.h",
         "src/core/lib/iomgr/sockaddr_utils.h",
         "src/core/lib/iomgr/sockaddr_windows.h",
@@ -874,17 +887,17 @@ grpc_cc_library(
         "src/core/lib/iomgr/sys_epoll_wrapper.h",
         "src/core/lib/iomgr/tcp_client.h",
         "src/core/lib/iomgr/tcp_client_posix.h",
+        "src/core/lib/iomgr/tcp_custom.h",
         "src/core/lib/iomgr/tcp_posix.h",
         "src/core/lib/iomgr/tcp_server.h",
         "src/core/lib/iomgr/tcp_server_utils_posix.h",
-        "src/core/lib/iomgr/tcp_uv.h",
         "src/core/lib/iomgr/tcp_windows.h",
         "src/core/lib/iomgr/time_averaged_stats.h",
         "src/core/lib/iomgr/timer.h",
+        "src/core/lib/iomgr/timer_custom.h",
         "src/core/lib/iomgr/timer_generic.h",
         "src/core/lib/iomgr/timer_heap.h",
         "src/core/lib/iomgr/timer_manager.h",
-        "src/core/lib/iomgr/timer_uv.h",
         "src/core/lib/iomgr/udp_server.h",
         "src/core/lib/iomgr/unix_sockets_posix.h",
         "src/core/lib/iomgr/wakeup_fd_cv.h",