Enhances/Fixes categoryList.tpl

Closes #1064
Makes Category a ProcessibleDatabaseObject
Resolves todo in PagesFunctionTemplatePlugin
Disallow print, is_null and create_function as well.
Merge branch 'master' of github.com:WoltLab/WCF
Validate declaration of use
UseDeclarationSniff checks for newlines between use-statements

cf. #987
Add Sniff that discourages use of raw PCRE

Closes #1054
Fixed badges in main menu
Merge branch 'master' of github.com:WoltLab/WCF
Fixed template handling in multi-app environment

Fixes #1076
Check whether imports are correctly ordered

Closes #987
Merge branch 'master' of github.com:WoltLab/WCF
Fixes permission calculation

This fix is relevant for user group option types that can have a list of values (e.g. list of usable attachments). In the database, only the difference between the default value and the user group's value is stored. This difference is calculated by `IUserGroupOptionType::diff()`. When the permissions for a certain type of user groups are calculated, the difference for all relevant user groups have to be merged, which is done by `IUserGroupOptionType::merge()`.

The code of the previous merge function is the same as the code of the new diff function. This worked fine when calculating the difference to store the values. But if the merge of two option values was calculated during the permission calculation for a certain type of user groups, again, the difference was calculated, not the merge. This had the effect, that if, for instance, the default value for the usable attachment types was "gif, jpg" and the value for the administrator group was "foo, jpg", administrators were only allowed to use "foo" attachments (which is the diff of the two) instead of "foo", "gif" and "jpg".
Merge pull request #1080 from Gravatronics/bug/permissionCalculation

Fixes permission calculation
Fixed template engine
Fixes SetupTemplateEngine::getCompiledFilename()
Fixes code to match PHP CodeSniffer rules
Merge branch 'master' of github.com:WoltLab/WCF into travis
Further CodeSniffer adaptions