* scm/output-ps.scm (define-fonts): Do not crash when encoding==#f

* scm/output-ps.scm (define-fonts): Do not crash when encoding==#f
(ugh?).

* scm/output-tex.scm (output-scopes): Check if variable is bound.

* scm/define-markup-commands.scm (fill-line): Use
make-simple-markup (WAS: unexisting make-word-markup).

* lily/text-item.cc (interpret_markup): Bugfix, transpose
ENCODING, MARKUP parameters for interpret_string.

* lily/include/book.hh:
* lily/book.cc: New file.