LuaJ String bugs

[SquidDev]

This aren't bugs with ComputerCraft but with LuaJ. I understand that this isn't within the scope of this bug tracker, just thought it might be useful.

• string.gmatch will loop forever on non-consuming patterns (such as \n*)
• \011 is not counted as whitespace.
• string.format does not pad/truncate on string of floating point format codes (%s, %f, %g, etc...)
• Balanced matches (%b) throw an out of bounds exception on no match

I've got a set of fixes and test cases if you want to fix/test this. This doesn't correctly handle the %g modifier.

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I've also added a fix for string.find returning the wrong index on a previous match (which I guess is what the string.find and string.match overrides in bios.lua are for).

[dan200]

Fixed the string.find bug in my LuaJ fork and removed the bios.lua hacks. May merge in the other fixes later.

[dan200]

Fixed the infinite loop, whitespace not matching \v (this is actually caused by a typo in the original code, which i corrected), and the out of bounds exception. I will not be implementing the string.format fixes due to code complexity and relative unimportance.

[SquidDev]

Awesome! Thanks.