Revert "Fix variable names beginning with numbers"

Save this commit for v0.3, Fix not yet updated in latest lg.jar
This reverts commit 554ae1c9bf6f93eba2e4dc8816a3b3647e43da34.
v0.2

Integrated PKU obfuscators.
Level 0 obfuscation testing complete.
Fix variable names beginning with numbers

Add '_' in front. Fxed #1 by Nels
Update keyword blacklist

Updated with lua syntax that was causing errors when testing as they
would get obfuscated.

Still not sure what to do with lua library functions like string.format()
or io.write() as the walker can't differentiate lua library functions from
program declared identifiers.