Rename to Twentronix Build Tools

Forked from Akeeba Build Tools at commit e572d9e2a1670d84e989f29843c515487ee6f702. Main reason was the hardcoded buildlang.php, see: https://github.com/akeeba/buildfiles/pull/4#issuecomment-23209724
Move building and link stuff to old_utils. Also remove nbproject directory
Readme update