changed constructors of entities classes, added fromJSON(), toJSON(), toString() methods.
finished "view card" back end part.
created new folder for covers (background images): original and mini.
added resources folder with fields_names file - names of all fields, that are using in database and JSON queries
added cover processor and cover entity class
added default fields values and fromArray(), fromJSON(), toJSON(), toString() methods
added publish() method to card_controller and necessary methods for this action to card_processor

added lang values
Some style (css) cleaning.
.htaccess security issues
Added input data validation.

Added method is Default() - return (boolean): if values of the object
are default
Removed Font and Size entities
JSON field changed, unnecessary validation cleaned
Added toolbar
Added js models: data, position, block
Added knockout and summernote libraries.
Added card_view_model, based on knockout framework.
Removed resource.php and card_class.js
edited .gitignore file