Fixed #68 "." in key causes error
- Now is possible to access keys with dots escaping '.' with '\' lua ["g_dot.key\\.with\\.dot"];
[NLua] Implemented operator + handling using metatable method __add.
- Missing tests
Updating Readme.md
Merge pull request #97 from gportela85/fix-readme

Updating Readme.md
[NLua] Added auto bind C# overload with Lua mats-methods (__add, __sub, __eq  etc).
[iOS][Android] Fixed iOS,Android build added missing System.Numerics reference.
[NLua] Fixed ValueType check https://github.com/NLua/NLua/commit/81d6d81b901c1cb7cec52cf1d73a49c993a3abe6#commitcomment-7216108
[NLua] Fixed #98 Don't use case-insensitive search for members