Adding in more mimetypes for fuller list (Bug #1302251)

Got the extra mimetypes from the list that moodle uses

Change-Id: I0794df03a7742226e0520aff5bdb86519a3dd67b
Signed-off-by: Robert Lyon <robertl@catalyst.net.nz>
Merge "Adding in more mimetypes for fuller list (Bug #1302251)" into 1.7_STABLE