Also shortens some related code and adds more parameters to string.split.

Changes:
  * Indentation with tabs by default.
  * Array keys dumped without "[i] = " prefix.
  * String keys that are valid identifiers aren't enclosed in '[""]'.
  * Basic support for multiple references (as specified in the comment).

These were initially added to get tracebacks for invalid vector errors, but it
didn't work and tracebacks have since been properly fixed in the core.

Changes:
  * Add comments to explain the dumping code
  * Add support for dumping values of any type (as '<' <type> '>')
  * Add support for tables as keys in dump2()
  * Make dump2() return it's result (like dump()) rather than printing it
  * Simplify and optimize function serialization via serialize()

Fix doubleclick not working in singleplayer
Fix of by one issue on accessing raw list
Fix this->self
Fix copy&paste error for scroll button

Fix crash on using cursor keys in client menu without selected server
Add support for non fixed size tabviews