Problem/Motivation
The BAT (base-admin-theme) file organization we started to do in Drupal 8 was a fantastic idea. See http://drupal.org/node/1089868
It works really well, but its names conflict with the SMACSS categorization we're using in Drupal 8. "base" and "theme" means something else in SMACSS. So we just need to rename them.
The system module does not yet follow these guidelines.
Proposed resolution
Rename module CSS files to match new file naming convention
eg. MODULE.base.css becomes MODULE.module.css.
MODULE.admin.css stays the same (but requires adding a MODULE.admin.theme.css so admin themes can override the default theme).
And MODULE.theme.css remains MODULE.theme.css.
Rename book module, comment, contextual, edit, field, forum, help, image, node, openid, shortcut, simple_test, taxonomy, tour, update, user CSS files to match new file naming convention
In addition, since our template files are now in a templates sub-directory of a module, we should do the same for the CSS. Note that the toolbar, tour and views modules already do that.
This is part of the CSS standard described at http://drupal.org/node/1887922
Remaining tasks
Need to clarify naming convention, refer tim.plunkett query at http://drupal.org/node/1921610#comment-7362724
User interface changes
none
API changes
The system.module's CSS files will have new names.