Milestone sage-2.8.2

GOAL -- fix bugs.

If we can fix all of the following bugs, this bug squash will be a MAJOR SUCCESS:

Mathematics:

#160 #190 (and #440) #201 #248 #254 #268 #274 #292 #303 #304 #316 #319 #337 #342 #350 #352 #392 #393 #429 #447

Interfaces:

#265 #275 #349 #420

Graphics:

#206

Notebook:

#224 #231 #240 #312 #321 #340 #402 #408 #446

Language:

#226 #293 (robertwb) #423

Other:

#371 #433 #441

Way too hard for now or really should be fixed upstream:

#389

These are not bugs. Changed to enhancement for later (not this SAGE release):

#227 #281 #291 #346 #351