No longer updating files along with the update
SQLParser only supports the CREATE INDEX syntax
Correct grammar in de.xml
Fixes DateUtil::validateDate()

Fixes WoltLab/WCF#1283 as gmdate returns a date in GMT but strtotime doesn't if input isn't specified as GMT.

See http://www.php.net/manual/en/function.strtotime.php
> Each parameter of this function uses the default time zone unless a time zone is specified in that parameter.```
Merge pull request #1284 from max-m/patch-2

Fixes DateUtil::validateDate()
User management optimizations
Merge branch 'master' of github.com:WoltLab/WCF
Fixed update
Removes unused code
Fixes PackageArchive::getConflictedExcludedPackages()
Fixes handling of excluded packages during package update

When a package is updated, the excluded packages of the current versions are deleted first and replaced by the new ones. This way, it's ensured that packages the current version excludes and which the updated version doesn't exclude anymore, are properly handled [cf. WCF 1.1].
Added missing update of language variables
Merge branch 'master' of github.com:WoltLab/WCF
Fixed inconsistent usage of elseif

In the past, elseif was used within templates. Now, you've mixed up the
usage of else if and elseif.
Merge pull request #1291 from SoftCreatR/consistentElseIf

Fixed inconsistent usage of elseif
Added missing language variables
Merge branch 'master' of github.com:WoltLab/WCF
Disabled language update server management
Resolved some todos
Fixed mail worker