PHP sux: Empty argument never be overriden with "" default parameter, so 'new Cache()' won't initializes with correct BOLT_CACHE_DIR
Merge pull request #1099 from rixbeck/master-org

PHP sux: Empty argument never be overriden with "" default parameter, so...
Merge branch 'upstream/master'

Conflicts:
	app/src/Bolt/Cache.php