ZKMTransformer

Some fixes for ZKMTransformer.
The PR fixes issues I had during ZKM deobfuscation which I only tested on one application. Due to my very superficial byte code knowledge I do not know if these chages would cause side effects for other applications/users.
The application now completely runs through for me, producing a new jar file, which was not the case previously. But not all Strings are deobfuscated yet.