Adds jquerycolorbox as conflicting extension

It provides its own old jQuery library that is used instead of the one provided by Arcavias
Merge https://github.com/Arcavias/arcavias-typo3
Adds release target to phing file for creating branches and tags
Merge pull request #109 from nsendetzky/master

Adds jquerycolorbox as conflicting extension and release target to phing file