Fixed: scroll wheel speed is way to low in firefox

I increased scroll wheel speed to a sensible value
formatting
Fixed: Ivars with accessors in a Category failed with duplicate ivar error
symbolic constant
Fixed: Added test case
fix cpcollectionview height issue
correction of height calculation
fix for missing textFieldBackgroundColor support
apply to contentView instead of bezelView
manual test
introduced cocoa methods for background color
changed test to use cocoa api
correction of typos
Test: Added Tests for non-english locales

CPDateFormatter only supports the "en" locale by default. All other locales yield empty results for most symbols. The tests added ensure, that the english "default" values are returned if no specific data is available (which is currently the case for every locale except "en").
Fixed: CPDateFormatter now works for non-"en" locales

CPDateFormatter previously only defined symbols for "en"-locale. Using another locale simple yielded nil-results for most keys. This fix addresses this behavior by always returning the english symbols as default unless other symbols have been explicitly provided or set.
Fixed: Updated backgroundColor internal variable handling

Previously, _textFieldBackgroundColor was used as the internal variable, and getter/setter methods were explicitly declared to handle getting/setting this value.

This commit changes the name of the internal variable to match the Cocoa compliant method (backgroundColor/setBackgroundColor). It also declares an @accessor option to auto-generate the getter. The setter is explicitly declared because it needs to mark the object as needing display.

Additionally, the logic for the setting is moved from the older method, setTextFieldBackgroundColor, to the new one, setBackgroundColor, and a comment was made to clarify that the older one was deprecated with a link to this issue.
Fix: Remove _backgroundColor

This parameter exists on CPView, so it has been removed here. A note was added on the setter to identify that the parameter was defined in the superclass.
Formatting recent changes.
Merge pull request #2155 from krodelin/CPDateFormatter-emptyLanguages

Fixed: CPDateFormatter now works for non-"en" locales [+1]
Formatting: CPDateFormatter changes and tests.

Refs #2155.