Compatibility with Pillow (a PIL fork).

git-svn-id: svn+ssh://svn.code.sf.net/p/mcomix/code@885 ef8490bc-f317-4725-81ed-e95a9aca1bcf
Fixed: #39 Double page mode: Optionally compute shrink ratio separately.

From: Valentin Gologuzov <imvalgo@gmail.com>

git-svn-id: svn+ssh://svn.code.sf.net/p/mcomix/code@886 ef8490bc-f317-4725-81ed-e95a9aca1bcf
Added double-page scaling fix to ChangeLog.

git-svn-id: svn+ssh://svn.code.sf.net/p/mcomix/code@887 ef8490bc-f317-4725-81ed-e95a9aca1bcf