cleanup precondition checking when creating new files / folders
- use i18n
- use trim when checking for empty file / folder name
- use more verbose error descriptions
add missing ;
cleanup array value assignment
use a more descriptive error message when the user tries to create '/Shared'
merge master with resolved conflicts
Merge branch 'master' into prevent_user_from_creating_or_renaming_to_an_existing_filename

Conflicts:
	apps/files/js/filelist.js
LDAP Wizard: proper strings and translations for user and group count text
Correct indentation for default language.
add missing file header
Fix coding style for else.
Better variable names.
Catch duplicate insertion errors while scanning files

When two scanning processed run at the same time, for example when
scan.php and list.php were called at the same time on an external
storage mountpoint, duplicate insertion errors can occurs.

These errors are now logged and ignored.

Since both scans are running in parallel transactions, they don't see
each other's changes directly in the DB which can cause duplicate
insertion errors for mime types as well, but those mime types can't be
selected yet. The solution to this is to force-reload the mimetypes list
after the transaction is finished.

Fixes #5199
Added $app parameter to logException
Merge pull request #5404 from owncloud/ldap_settings_wizard

Ldap settings wizard
Update CONTRIBUTING.md

Gave more info on how to search issues.
Merge pull request #5458 from owncloud/fixing-5222-master

php 5.3 compatibility regarding OC\DB\Connection fixed
Fixed wrong id when reading checkbox value for force SSL setting

Fixes #5488
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.