Revert "Issue #1356602 by nicholasruunu, mcjim, rteijeiro, chrisjlee | jenlampton: Clean up icons in misc."

This clean-up accidentally introduced a few regressions, so rolling back until it's ready.

This reverts commit fab42693.

Nate Lampton authored Oct 30, 2011 and catch committed Nov 01, 2011

Issue #22336 by quicksketch, scor, boombatower, and rfay. Move all core Drupal files under a core subdirectory.

#874370 by Jeff Burnz, aspilicious, Cliff, mgifford, yoroy, et al: Fixed System messages need identifying icons (WCAG 2.0).