Make it easier to update patches and apply them manually

Clean the way that we maintain patches by keeping them ordered by
their number and let the shell order them when giving the list to
git am.

Provide a update-patches.sh that maintains the proper command lines
to use and run a cleaning script on the resulting patch to avoid
the SHA1 to be added to the file as it changes every time the patch
is applied.

Change-Id: Ia93cf4b35f5f847a8723a31fc476443864242737
Reviewed-by: Andras Becsi <andras.becsi@digia.com>