migrate: Fix old default value of colorCommentScore
migrate: Force a migration for v4.5.0.3

Fixes #1411.
showNotification() defers showing notification until document.body is ready
migrate errors should show stack trace
mark all migrations done on fresh installs
4.5.0.2 didn't set RESOptionsVersion for fresh installs
show notification about voteEnhancementsoptions.colorCommentScore getting reset to default

fixes bad 4.5.0.1 migration
RESOptionsMigrate.general.forceUpdateOption

it'll be necessary sooner or later
don't do any migrations if a previous migration broke the RESOptionsVersion value
colorCommentScore migrator handles default, non-default, and v4.5.0.1 bug
mark notification opened
ignore manual close if notification is already closed
Merge pull request #1438 from andytuba/migrate_enh_1416

migration fixes and notification