Convert OC_Appconfig to object interface

Implemented unittest for OC\AppConfig
check for valid appinfo in installer
Style fixes
Enable appconfig asserts
Merge branch 'master' into convert-oc_appconfig
Move legacy file to correct location
Add a FileInfo class which holds all info of a file and return that from getFileInfo, getDirectoryContent and search
Extends phpdoc for \OCP\File\FileInfo
remove ArrayAccess, JsonSerializable from the public part of FileInfo
add Support for passing a FileInfo instance to View->putFileInfo
Merge branch 'master' into fileinfo
Don't use is_array on FileInfo
Dont use php5.4 only features
remove more is_array from encryption
Merge branch 'master' into fileinfo

Conflicts:
	tests/lib/files/cache/cache.php
undo 3rdparty change
undo 3rdparty change
Add isReadable, isUpdateable, isDeletable, isShareable
Reuse the calculated free_space in buildFileStorageStatistics
merge master into fileinfo