Fix some bugs.

[m-imperfect]

Fixed:

1. Escape lua keywords in table string keys according to and is not escaped properly #6.
2. Escape backslashes in strings according to \ is not escaped properly #5.
3. Support multi-line strings / Escape new lines in strings, according to New line in string value causing issues #3.

TODOs:

• Configure labels.
• Provide more syntax error info.

[Eejit43]

@kcwiki it would be great to get this merged! :)