Include license information for libs folder in distrubution

[Shoozza]

To make distribution easier, a ready to copy & paste license.txt for the third-party dependencies (the libs folder) would be helpful.

See löve license.txt for a template.

While most of the libraries don't require attribution in a binary release at least the optional lust library (MIT License) does.

Additionally the strict.lua is possibly taken from https://github.com/moai/moai-dev/blob/develop/3rdparty/lua-5.1.3/etc/README and was further modified afterwards. It has no license information (was public domain initially). This would be easier to track with a license file.
Optionally a newer version of strict.lua could be taken as it is/was part of the lua source code distribution which since has updated the license of strict.lua to be the same as the lua license.