loader: PSD: Propagate errors correctly.

Fix error propagation from combined image loader.

Signed-off-by: Cyril Hrubis <metan@ucw.cz>
loaders: TIFF: Fix Big Endian signature.

It's "MM\0*"

Signed-off-by: Cyril Hrubis <metan@ucw.cz>
doc: Minor css style tweak.

Signed-off-by: Cyril Hrubis <metan@ucw.cz>
doc: Add GFXprim to specialwords.

Now all occurences of GFXprim are emphasized automatically

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