Fix missing CMAKE_BUILD_TYPE in 'cmake ..' scenario (#413)

Led to the following CMake error on 3rdparty deps build when `cmake ..`
is only specified:
```
CMake Error: Invalid value used with --config
```

Author: aobolensk

cmake/configure.cmake

@@ -6,6 +6,10 @@ if (APPLE)
     set(CMAKE_SHARED_LIBRARY_RUNTIME_C_FLAG TRUE)
 endif(APPLE)
 
+if (NOT CMAKE_BUILD_TYPE)
+    set(CMAKE_BUILD_TYPE "Release")
+endif(NOT CMAKE_BUILD_TYPE)
+
 set( CMAKE_ARCHIVE_OUTPUT_DIRECTORY_DEBUG "${CMAKE_BINARY_DIR}/arch" )
 set( CMAKE_LIBRARY_OUTPUT_DIRECTORY_DEBUG "${CMAKE_BINARY_DIR}/lib" )
 set( CMAKE_RUNTIME_OUTPUT_DIRECTORY_DEBUG "${CMAKE_BINARY_DIR}/bin" )