added basic chat UI
creating dummyFragment for non-chat cases as it was throwing a
NullPointerException
the NullPointerException seems to be from the ChatFragment (couldn't
figure that out from the Logcat output). I think I need to use the false
as the third parameter on the inflater.inflate() method.
changed titles for fragments to relevant ones
created new FileTransferFragment fragment and an associated layout file
externalized Strings in chat layout
filled the file_transfer.xml and externalized strings
created VideoFragment and the associated empty layout file