Resolve a good chunk of windows compiler warnings

Mostly revolved around the new MSVC check for functions that don't cover all paths (ie. a switch statement without a default case).  It appears to not see an assert as a valid default case.

I switched assert(false) to exceptions in these cases.  I believe this should also abort the program, but will also provide a hopefully useful message?  Hopefully this is an improvement.

Resolves #32

decompiler/Disasm/Instruction.cpp

@@ -26,7 +26,7 @@ std::string InstructionAtom::to_string(const LinkedObjectFile& file) const {
     case IMM_SYM:
       return sym;
     default:
-      assert(false);
+      throw std::runtime_error("Unsupported InstructionAtom");
   }
 }