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