Cache: add seccond mtime field
Cache: bookkeeping of storage_mtime
Emulate touch() for backends that don't support it
merge master into filecache_mtime
Merge branch 'master' into filecache_mtime

Conflicts:
	lib/files/view.php
	lib/util.php
	tests/lib/files/cache/cache.php
merge master into filecache_mtime
Merge pull request #1586 from owncloud/filecache_mtime

Emulate touch() for backends that don't support it