chapter on lua
first pass at lua chapter
Remove TeX-related lines from the Markdown source.
Change the existing XeTeX template with another one.

The merged template is the same used for The Little MongoDB book.
Add the title text file.

The same thing as for The Little MongoDB book.
Add Makefile for books building.

The same thing as for The Little MongoDB book.
Add the git-ignore file for output books.
Change section levels in the Markdown source.
Update the readme file with building instructions.
Merge pull request #28 from ming13/improve-books-building

Improve books building
fixed title
fixed typo
Typo: repeated "and".
Merge pull request #29 from FGM/master

Fixed typo
Keeping 50 items needs to use ltrim 0 49, not ltrim 0 50.

- Typo, wording in Lists and in Sets.
Merge pull request #30 from FGM/master

Ltrim parameter error and typo
Change fonts commentary in the readme file.

Related to issue #26.
Merge pull request #31 from ming13/fonts-warning

Change fonts commentary in the readme file
added link to spanish translation
rename keys to ids to properly represent the fact that llrange returns values, not keys