New debugging features, cellGame & minor changes

Two cellGame functions partially implemented:
- cellGameGetParamInt
- cellGameGetParamString

New debugging features:
- Call Stack viewer added
- Memory Viewer rewritten (Not finished yet)

Modified definition of UNIMPLEMENTED_FUNC to improve compatibility with
other compilers: Thanks @krofna

Replaced the "Compiler" menu entry with "Tools" and "Memory Viewer"
entry added.

NOTE: To "quickly" browse the memory using the Memory Viewer you can use
the scrollbar. Notice the irony of the word 'quickly' since the memory
viewer is actually slow as fuck. I will fix that soon. As you can see,
I'd like to add a Raw image viewer in the future in order to "see"
textures directly from memory.

rpcs3/Emu/ARMv7/ARMv7Thread.cpp

@@ -39,7 +39,7 @@ void ARMv7Thread::SetArg(const uint pos, const u64 arg)
 
 wxString ARMv7Thread::RegsToString()
 {
-	wxString result;
+	wxString result = "Registers:\n=========\n";
 	for(int i=0; i<15; ++i)
 	{
 		result += wxString::Format("%s\t= 0x%08x\n", g_arm_reg_name[i], GPR[i]);