The FLAGS variable is factorized independently of the ONLINE mode.
The OPTIONS variable is now based on LINUXINCLUDE and explicit
includes are thus removed.

The format of the -I option differs between gcc and spatch.
The COCCIINCLUDE is used to adapt the format. This rewritting
needs bash.
Signed-off-by: Nicolas Palix <nicolas.palix@imag.fr>
Signed-off-by: Michal Marek <mmarek@suse.cz>