Implemented image upload api functionality.

 - Images are uploaded to a folder specifiled in local_setting.py file (see local_settings_template for example)
 - The view uses special file names generator which allows to avoid duplicates
 - Database schemachange included.

Refs, #152
Fixed small typo in code comment
Merge from live to image_upload
Image upload for Image API. Added MEDIA_PATH variable to settings.
Merge branch 'images_upload' into live