filters: GaussianNoise: Set errno.

Set errno to EINVAL on unsupported pixel types (palette).

Signed-off-by: Cyril Hrubis <metan@ucw.cz>
filters: ResizeCubicInt: Set errno.

Set errno on invalid pixel types.

Signed-off-by: Cyril Hrubis <metan@ucw.cz>
tests: filters: Fix filters compare.

Some of the filters cannot run in-place, fix it by passing src as the
first arg.

Signed-off-by: Cyril Hrubis <metan@ucw.cz>
backends: X11: Avoid warning on GravityNotify

Avoid useless warning on GravityNotify event.

Signed-off-by: Cyril Hrubis <metan@ucw.cz>
filters: GaussianNoise: Set errno.

Signed-off-by: Cyril Hrubis <metan@ucw.cz>
text: Add va_list variant for GP_Print()

Signed-off-by: Cyril Hrubis <metan@ucw.cz>
spiv: Another cleanup.

Shuffle the code a bit, remove unused cruft.

Signed-off-by: Cyril Hrubis <metan@ucw.cz>
doc: Add AALib to supported backend in general info.

Signed-off-by: Cyril Hrubis <metan@ucw.cz>
spiv: Rewrite configuration, add config file.

* Rewrite spiv command line parameters parsing
  (adds long options)

* Add support for configuration files
  (now it tries /etc/spiv.conf and ~/.spiv)

* Add --print-man switch to generate man page

Not finished yet, more will come soon.

Signed-off-by: Cyril Hrubis <metan@ucw.cz>