Add in liblua-* variant for Linux lua library names (resolves#3678)
Remove some more unused NLua code
Make LuaState internal, we don't need to see it (NLua.Lua API slightly changed to accommodate this, tests could be broken due to this?)
Make various other NLua classes internal, we don't need to see them
Check against lua library loading failing, provide a non-fatal message box if it has failed instead of crashing on some exception.
Remove UnixSearchPaths (unneeded with LD_LIBRARY_PATH being set) and unused IImportResolvers
combine NLua with KeraLua (KeraLua is "gone" now I guess)
make it use the BizInvoker (so now it can properly handle the liblua5.4.so and lua54.dll names differing), also delete the liblua54.so.
minor speedup when creating a new empty table
make lua default to UTF8 internally, so we don't need to manually change the state's encoding
YoshiRulz