Allowing the .zip files to be detected by file extension (Bug #1302251)

A number of filetypes are being detected as a zip file, due to them
having compression.

To sort this out we will let the file extension be checked first then
fall back to checking magic.mgc.

Change-Id: Iab6ddbc17af4018cf381c4949172804acff49483
Signed-off-by: Robert Lyon <robertl@catalyst.net.nz>
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 "Allowing the .zip files to be detected by file extension (Bug #1302251)" into 1.9_STABLE
Merge "Adding in more mimetypes for fuller list (Bug #1302251)" into 1.9_STABLE