Add licensing info as input files

Add two files with copyright notice and the full licenses as .inp files.
They are placed in the OLLlatex folder where they are found automatically.

They should be included in every OLLbook.
Add LilyPond-Tutorials compilation book

Book stub for the inclusion of tutorials
Individual texts should be inserted through the subfiles package
(Maybe this one has to be installed separately)
Dump individual tutorial LaTeX class

Tutorials don't have their own documentclass,
but are rather implemented using the subfiles package.

So the initial stub can be removed
Consolidate LaTeX classes and style files

For now we will have only one class file: OLLbook.
We won't produce one "Big Book" but rather a few smaller ones:
- OLLib documentation
- OLLexamples and OLLincludes
- Tutorials
Each one has OLLbook as its documentclass.
The individual parts of these books are written in 'subfiles'