Fix sharing error message - id -> file name

fixe #2827
Inject memoryCache into Autoloader. Remove recursion-prevention hack.
Only use autoloader cache when 'instanceid' is available.
Only write-back on cache miss.
Allow null as cache parameter (if no cache was found) and for cache removal.
added stripped library php-opencloud (version 1.6.0)
adjustment of the configuration parameters
adapted existing test cases
renaming OC\Files\Storage\SWIFT to OC\Files\Storage\Swift
rewrite of OC\Files\Storage\Swift
make Swift::testLocal workable by fixing the prefix used with the object listing in opendir
Revert "make Swift::testLocal workable by fixing the prefix used with the object listing in opendir"

This reverts commit b92061da5ab2d11f803731628c4304aa8cd302e3.
make Swift::testLocal workable by using a delimiter
Correct indentation for default language.
Fix coding style for else.
Better variable names.
Apply substring on the correct value.
Sort, so 'de' is preferred over 'de_DE' when performing non-exact matching.
Have to also strtolower() on available language name. Otherwise no match.
Some tests for OC_L10N::findLanguage()