* input/regression/markup-bidi-pango.ly: new file.
* lily/pango-font.cc (pango_item_string_stencil): make Mingw code
standard. Remove #ifdef. Remove memleak.
(text_stencil): use text_dir to decide how to composite items.
(text_stencil): determine uniform text direction for the entire
string.
* scripts/lilypond-book.py (output_name): remove
latex_filter_cmd. Non-portable to non-Unix systems.
(get_latex_textwidth): use File.write and os.unlink() instead.