Update MethodSignature.java

Adding getExceptionNames() method to return array of internal names for each exception (as required by MethodVisitor).
Update MethodAdder.java

Fixing ArrayStoreException in MethodAdder constructor. Removing (now) redundant copy of mExc array since a new copy of the array is constructed by each call to getExceptionNames().
Update MethodSignature.java

Indentation
Update MethodSignature.java

Removing tabs plus minor changes to getExceptionNames().