small fix
better option parsing for "vips"

The vips driver program was parsing options in a single pass. This
failed if an option came in two parts, for example:

	vips --plugin x.plg list

the argument to --plug would be picked up as the action for "vips",
since actions were selected before option parsing

Now we parse in two passes: the first pass picks up options for vips
itself and for the libvips library, then we select the action, then we
parse again, including any options created by the action
Merge remote-tracking branch 'origin/7.30' into 7.30
Merge remote-tracking branch 'origin/7.30'

Conflicts:
	ChangeLog
	configure.in
Merge remote-tracking branch 'origin/master' into corner
fix up affine

now passes valgrind with both vips7 and vips8 interfaces