Find LyX even on non-MacOSX

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Run commands quietly, but show output and exit on failure

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Run elyxer even from the PATH

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Fix relative paths after changing the directory

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Remove generated files

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Ignore generated files so they won't be committed again

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Override obsolete geometry package on Ubuntu

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>