FIX Privilege escalation through Group and Member CSV upload (SS-2013-004)

See http://www.silverstripe.org/ss-2013-004-privilege-escalation-through-group-and-member-csv-upload/
Tagged 2.4.12
Tagged 2.4.13
Merge tag '2.4.13' into 2.4
BUGFIX Load jquery before leftandmain.js in upload iframe for assets
Merge pull request #958 from tractorcow/pulls/2.4-merge-#955

BUGFIX Load jquery before leftandmain.js in upload iframe for assets
Update travis configuration to use composer phpunit
Merge pull request #1012 from silverstripe/pulls/2.4-travis

Update travis configuration to use composer phpunit
Merge remote-tracking branch 'origin/2.4' into post-2.4

Conflicts:
	composer.json
Fix parse error