Feature/searchlocations bug fix

bug fix:
The actual method:
- (void)searchLocation:(BPSearchLocation *)searchLocations callback:(BuddyCollectionCallback)callback
in BPLocationCollection doesn't work as expected because the BPSearchLocation properties are not sent to the server.
This is due to the fact that class_copyPropertyList doesn't copy superclass properties (https://developer.apple.com/library/ios/documentation/cocoa/reference/ObjCRuntimeRef/Reference/reference.html#//apple_ref/c/func/class_copyPropertyList)
To correct this, I've added the BPSearchLocationProperties in BPLocation.h. And BPSearchLocation now implements this protocol.