Fixed copyright notes
- Made sure all files contains an @author tag specifying the author(s) of the file
- As agreed, the library will be Open Sourced under Twitvid Inc. copyright. All old/original code based from Twitvid work contains an Apache License 2.0 note. All new code still mentions Twitvid in the Apache License note, even if it was written on the author's spare time.

List of files under Twitvid Inc. copyright:

DownloadUtils
DeviceStatus
GroundyService
GroundyTask
GroundyTaskFactory
L
WakeLockHelper

Classes not mentioned above were written on my spare time and, thereby, contain an extra line in the license note.