add migration for 4.5.0.2

fix bugs:

- move oldValue / newValue definition into try/catch as they can fail / bomb out
- fix updateValue call in updateOption - had 3 params, needs 2
- move oldvalue / newValue definition into try/catch for moveOption also, same reason
- in moveStorage, "value" was passed, nonexistent var.. set to oldValue although oldValue isn't evenn used - will refactor shortly...
- legacyOptionVersionMapping index needed a 1 subtracted ("2" gives us 2nd value in array, which is index 1)
- fixed getVersionNumbers() call (preceded by wrong variable name)
- removed unnecessary version number from legacy array
- fixed getVersionNumbers call
optionName -> oldValue
migrate: Make migration function name consistent
Merge pull request #1402 from mc10/migrate

migrate: Make migration function name consistent
migrate: Fix calls to functions
Merge pull request #1403 from mc10/migrate

migrate: Fix calls to functions
migrate: Another one...
migrate: Fix incorrect variable names
Merge pull request #1404 from mc10/migrate

migrate: More bug fixes
rework updateOption to ensure it doesn't blow away a user-customized option during migration. option will only be updated if the "oldValue" is equal to the "former default value"
refactor out the option equivalence check to a separate function for better organization / readability.
instanceof -> Array.isArray
update comment
clean up showExpandos CSS rule, shouldn't / doesn't need !important
style cleanup in revealImage function, and replaced expensive jquery is visible call with cheaper offsetParent check
showImages: Rework code, remove duplicated code