Add a check to WeakTable

This is probably wrong, but what debugging and results show this fixes
LuaJ crashing on boot and randomly breaking
Fix error in OsLib

give the letter not the ascii code
Fix collectgarbage

Default is now collect, all options are now listed, and error message
changed.
Fix collectgarbage

Converted String switch case to if statements
Merge branch 'LuaJSucks' of https://github.com/gamax92/OpenComputers