Added task to remove expired invitations
Resending and removing invitations after a specified time
Add delete invitation button
Small refactoring
Merge branch 'master' into uservoice-pending-invitations
Update the text when invitation is expired
Merge branch 'master' into uservoice-pending-invitations

Conflicts:
	corehq/apps/style/static/style/lib/bootstrap-3.2.0
Merge branch 'master' into uservoice-pending-invitations

Conflicts:
	corehq/apps/style/static/style/lib/bootstrap-3.2.0
Code refactoring
Merge pull request #4179 from lwyszomi/uservoice-pending-invitations

Added task to remove expired invitations