Import of multiple-images support
Multiple sortable images can now be selected per page
Configurable background slider module implemented
Background slider implemented and method adjusted
Merge branch 'multiple-images' into develop
Fixed IE<9 issue
Make sure max-width is not set in CSS (Contao 3)

It would break image size/ratio calculation
Added option to disable horizontal centering of the image
CS
Added options to set minimum image width and height
Fixed image resize issues
Do not autostart slide if not more than one image
CS
Support Apache 2.4 in .htaccess file
Renamed changelog to markdown
CS
Added compresses script
CS
SQL definitions are now in the DCA
All fields should be excludable