Rotable cleanup 1

[chowette]

This cleanup set is focused on the rotable usage

• add and use LNEWLIB macro to load regular table or rotable with the same code
• remove old macro setnvalue() left from a previous lua version
• make the compatibility library bit32 a rotable
• some fix to remove obvious compilations errors when disabling LUA_USE_ROTABLE

[jolivepetrus]

@chowette,

Thanks for this PR. Unfortunately it can't be merged, because there are conflicts that must be resolved. Can you review it?.