Find method by opcode in Namespace/Class #38

Makes finding private obfuscated methods in an Assembly with ongoing releases easier.
In my case I most often know which class I need to patch so there is no need to search through everything. In fact it makes it more difficult by needing larger signature. I suggest adding optional parameters to Patcher.FindMethodsByOpCodeSignature(OpCode[] signature, string namespace=null, string class=null).