bbm (deluxe paint enhanced images) support

[gilles504]

[edit] oops, sorry for double post... I use MP version (& I was thinking post did not work)

It seems that most of my old *.bbm files (from deluxe paint studio enhanced PC/DOS version) are not correctly displayed (XnView MP Linux Version 0.93 64bits (Jan 31 2019) Libformat version 7.25).

Capture du 2019-02-04 15-21-48.png

If I remember correctly there is a trick for odd pixel width.

but it may also be compression (RLE packing) not correctly handled here.