Fix crash when first responder isn't a text view
Move a bunch of profiles code over to ProfilePreferencesViewController
Improve organization of ProfilePreferencesViewController
Move prefs migration code to iTermPreferences
Fix a bug where the character encoding wasn't initialized when prefs was opened for the first time because PreferencePanel's awakeFromNib was only called after ProfilePreferencesViewController's awakeFromNib returned.
Get rid of silly onScreen method in PrefPanel, and fix a bug where awakeFromNib actually needs to run twice in PrefPanel (once for shared and once for sessions instances)
Move startup code out of PrefPanel and into iTermPreferences
Move bulk copy to its own file and xib
Rename removeBookmark to removeProfile
Rename addBookmark to addProfile