Added set of constants to User class, removed "magic" constants.

System version 0.373
modules:
Blogs 0.069
Comments 0.020
Cron 0.008
Disqus 1.0.1+build-2
Feedback 0.006
HybridAuth 2.1.1-cs31
OAuth2 0.030
Photo_gallery 0.015
Plupload 2.0.0-cs2
Static_pages 0.037
plugins:
Admin_default_theme 0.005
Fotorama 4.4.6-cs1
SimpleImage 2.3-cs1
TinyMCE 4.0.9-cs3
\cs\DB\Accessor now trait, not abstract class. \cs\CRUD trait added.

System version 0.374
modules:
Blogs 0.070
Comments 0.021
Cron 0.008
Disqus 1.0.1+build-2
Feedback 0.006
HybridAuth 2.1.1-cs31
OAuth2 0.031
Photo_gallery 0.016
Plupload 2.0.0-cs2
Static_pages 0.038
plugins:
Admin_default_theme 0.005
Fotorama 4.4.6-cs1
SimpleImage 2.3-cs1
TinyMCE 4.0.9-cs3