#21 Move book files

[Baradé]

Currently we have doc/Jass++ and wc3lib/doc/lang directories for custom scripting languages definitions. Add new directory "book" for files of book "Warcraft 3 The Frozen Throne Modification" and move those directories in the new one.
The book should contain information about all available scripting languages (including JASS++), other Warcraft 3 related formats, the World Editor and other tools.
It should be created by using LaTeX.