Added Export Project Files functionality.  Issue #2038.

Conflicts:
	app/src/info/guardianproject/mrapp/media/MediaProjectManager.java
Added Sharing to Export Project Files functionality.  Issue #2038.
Edited menu label and moved string from code to strings.xml.  Issue #2038.
Fixed bug where checking for storage space.  Issue #2038.
Edited where files are exported.  Issue #2038.