Fixes  #157
Build: fix git command execution on some environment
Build: fix current path after running zip
Merge branch 'jelix-1.3.x' into jelix-1.4.x
Merge branch 'jelix-1.4.x' into jelix-1.5.x

Conflicts:
	build/buildapp.php
	build/buildfonts.php
	build/buildjbt.php
	build/buildjelix.php
	build/buildjtpl.php
	build/buildmodules.php