[libdvdnav-devel] Rebase Diego's buildsystem branch

[Jean-Baptiste Kempf]

Rebase Diego's buildsystem branch

Please double-check the 6th patch

[PATCH 1/8] build: remove non-autotools based build system.
[PATCH 2/8] configure: drop broken cross-compiling note.
[PATCH 3/8] build: rewrite build system to not be recursive.
[PATCH 4/8] Add a .gitignore file.
[PATCH 5/8] build: drop dvdread-config and dvdread.m4.
[PATCH 6/8] build: cleanup configure
[PATCH 7/8] Update base documentation.
[PATCH 8/8] build: install basic documentation files.