Added mimetypes for .bmp files.
http://filext.com/file-extension/BMP
Added mimetypes for corel draw files.
http://filext.com/file-extension/CDR
Made file mimetype and extension guessing more robust.
Used the ALLOWED_MIMETYPES mapping dictionary to generate EXTNS to use instead of image_formats() to check for formats that can be resized by imgee.
Corrected error in previous commit
Corrected error in previous commit
Made extensions in the ALLOWED_MIMETYPES mapping dictionary unicode, as they will be used in the database.
StoredFile needs to be provided with unicode values for title and mimetype
Store width and height for svg