Add image gallery
Move colorbox files into /image-gallery/lib/colorbox
Move common files into common and common-wl

- get-available-sites and get-user-data get moved into /common-wl
- get-plugin-dialog-html can be used across all the plugins, so /common
Add bind-folder-listing-to-preview.js to /common-wl

Used for image-gallery and folder-listing
Fix path urls and change getImageGalleryDialogtHtml to getPluginDialogHtml
Load bind-folder-listing-to-preview.js in dialog
Fix dialog css
Remove console logging and slimbox code (since colorbox is used instead)
Add console logging
Remove console logging
Fix urls on example
Update paths in README file
Merge pull request #11 from ox-it/image-gallery

Image gallery