Refactor CiviCRM CSS files

Objectives include:

• reduce weight
• eliminate obsolete classes / declarations
• maximize theme-ability

(Kyle will be posting details on the blog - and project goals / specifications will be fleshed out after community discussion).

Specific fixes:

• remove "bad" CSS

• replace civicrm icons with jquery-ui icons where possible

• organize civicrm.css into sections so that they can rbe replaced later

• remove unused css

• simplify css calls (padding: 4px; instead of padding-left:4px;padding-right:4px etc...)

• use css with border to style action links in selectors (replaces the 'pipe' (|) simple) - classes should make it easy to modify look and feel of these links.