Support Custom Fetch Result

[felix-dumit]

I had a scenario where I wanted to use the picker to select the assets among an already established PHFetchResult, without the need to show all the albums.

Now you can set the pickFromFetch property of the picker which will enable this option.

example:

CTAssetsPickerController *picker = [[CTAssetsPickerController alloc] init];
 // set delegate
picker.delegate = self;
// set custom fetch
picker.pickFromFetch = [PHAsset fetchAssetsWithOptions:nil];

[1and2papa]

@felix-dumit Sounds cool. Unfortunately I am very busy on my personal matter recently and this PR might not be merged within short period of time. Hope you don't mind.

[1and2papa]

Sorry, development of this project is suspended. This PR would be merged.