HackStudio: Assorted improvements to C++ highlighting

Add a list of hard-coded standard types (including AK types) and show
them in a different style.

Rehighligt the file whenever it changes. (This is very inefficient but
makes it much easier to experiment.)

Also keep tweaking the colors. :^)

DevTools/HackStudio/CppLexer.h

@@ -21,6 +21,7 @@
     __TOKEN(Comment)               \
     __TOKEN(Number)                \
     __TOKEN(Keyword)               \
+    __TOKEN(KnownType)             \
     __TOKEN(Identifier)
 
 struct CppPosition {