* lily/GNUmakefile (MODULE_LIBS): link with kpath-guile

* lily/GNUmakefile (MODULE_LIBS): link with kpath-guile

* lily/all-font-metrics.cc (kpathsea_find_file): wrapper around
new ly:kpathsea-find-file

* kpath-guile/kpath.c: new file. Put kpath bindings in lib.

* kpath-guile/GNUmakefile: new file

* scm/font.scm (add-music-fonts): load dynamics/numbers through
fontconfig as well.

* mf/GNUmakefile: generate .commonff to not confuse fontconfig.

* lily/main.cc: only look at one prefix directory, LILYPONDPREFIX
overrides all.

* config.hh.in: use lilypond-Major.Minor as data directory.