- Addednew open panel implementation. All/only API is via the NSOpenPanel class. Most of it is functional. There are TODO notes in NSOpenPanel.h
CK2FileCell:
- Changed to truncate in the middle, like Finder/OpenPanel does.

CK2IconItemView:
- Fixed assert.
- Replaced broken history implementation with NSUndoManager.
- Added formatting for file sizes to match with Finder.
- Fixed cleanup of operations data structures. Other tweaks.
CK2OpenPanel.xib:
- Removed search field. Move progress indicator to its spot.

CK2IconView:
- New class.
- Subclass of NSCollectionView. Done mostly to handle type selecting (selecting items when typed). Moved other icon view layout/tile code from the controller here.

CK2OpenPanelControler:
- Fixed bug when browser was being clicked where item was flickering as it was being re-selected.
- Got rid of code to tile the progress indicator now that it's no longer in the bottom left next to the "new folder" button.
- Added browser preview.

CK2IconView:
- Fixed bug with notification center registration/deregistration.

CK2OpenPanelBrowserViewController:
- Fixed type select.

CK2OpenPanel.xib:
- Tweaked minimum browser column width.
- Added size formatter to preview's size field.
- Fixed spacing between name field and the separator.
- Separator no longer a separate view. It is now drawn as a gradient by the preview view to resemble that in NSOpenPanel.
- Cleaned out some unused code.
- Added support for multiple selection. API-wise, you can use either URL or URLs as you can with NSOpenPanel.

NSURL+CK2OpenPanel:
- Added -URLByDeletingTrailingSlash. Code was moved from CK2OpenPanelController.
- Added support for allowedFileTypes.
- Fixed directories being disabled. They should always be selectable (so the user can see their contents) even if they ultimately cannot be selected as the URL by the panel itself. In other words, they should always be selectable in the UI but the OK button should only be enabled if it is allowed by the panel's settings.
- Made it so that controllers adjust the selection. The outline view can select files across directories so when you switch to one of the other views, the selection is a subset of what was viewable before. To emulate the behavior of NSOpenPanel, when switching back, you will have lost the parts of the selection that the other view could not display.

CK2OpenPanelController:
- Fixed memory crasher.
- Fixed UI being out of sync after session is reset.
Merge remote-tracking branch 'upstream/curlhandle-4' into curlhandle-4

Conflicts:
	Connection.xcodeproj/project.pbxproj
Connection.xcodeproj:
- Some files lost in the merge. Added them back to the project.

CK2OpenpanelController:
- Removed some test code.
Added support for setting a message and accessory view on the panel. Also added -validateVisibleColumns for when the accessory view may need to refresh the file listing based on its settings.
Re-enable default -stop behaviour
Paul had had to comment it out in 27426f863933973a318f8bacad214899c5a4008f as CK2FileProtocol did not yet handle it at all gracefully
Adopt -presentError:modalForWindow:… over NSBeginCriticalAlertSheet
Cleans up a warning and gives a nice sheet for us
Remove empty ivar braces
Might as well save a little space
Prefix NSURL category methods
@synthesize controller
Properly tear down panel<->controller relationship under manual reference counting
Make URLs absolute to clean up later comparisons