Do not load Imagick library if option is not set

Imagick will still load on the image options tab so that it can be
enabled.
French update
French update
#503
fix #514
fix #503
Revert "fix #503"

This reverts commit eb39d21c76543f1c61b1d07bc83a2c2c9d8927d9.
Something for #503
use if IN <set> better SQL efficiency than an extended compound equality list
Merge remote-tracking branch 'origin/master' into 1.4.6

Conflicts:
	zp-core/locale/fr_FR/LC_MESSAGES/zenphoto.mo
	zp-core/locale/fr_FR/LC_MESSAGES/zenphoto.po