Removed useless files

	Fragments which are not used for
	implementation have been deleted
UserDatabase activity removed

	Add and Update dialog boxes could be directly
	called from ManageUser
	Basically, proceeding towards reducing activities
	and improving user interface
Fixed Bugs and delete implemented in ManageUser

	* Delete dialog box is now called from
          ManageUser
	FIXED:
	* Cancel button from add used to close
	  ManageUser
	* Empty password not accepted
Removed useless delete fragment and activity files

	Delete is now implemented using dialog box
	in Manageuser itself
Moved MainActivity to ui directory