Add missing language items and improve some others

see #55
Add TODO
Remove obsolete less
Clean up LESS a bit

see #54
Ignore errors when setting local storage for duplicate tab protection
Use unless + is instead of if + isnt
Clean up CoffeeScript a bit
Add phpcpd check to travis.yml
Make phpcpd more verbose
Remove obsolete CHAT_LOG_ACTIVE option
Remove obsolete javascript file in javascriptInclude
Show more meaningful error message when alias is invalid

Closes #11
Add min and max attributes to datepicker in chatlog

see WoltLab/WCF@b9e59fc3b478f7723b2752a74d90226df8cf53b7
Add SuspensionAction::$requireACP

Closes #59
Fix formatting of PHPDoc in SuspensionAction
Merge branch 'master' into attachments

Conflicts:
	template/javascriptInclude.tpl
Improve attachment system

Now it's possible to upload attachments and generate an attachment
message. The attachments are registered in the database correctly and
can be viewed WCF's attachment list in ACP.

TODO: Proper design in frontend and some backend functions.