Editing

[heyhuyen]

Issue: https://github.com/codepath-android-fall16-group-8/travel/issues/33

Some basic editing:

• Delete whole trips (from create story and story screen, the latter includes a dialog confirmation)
• Deleting story place (fixed https://github.com/codepath-android-fall16-group-8/travel/issues/22 bug)
• Can edit/delete "text" media items

Also used butterknife and string formatting to cleanup toolbar titles.

Not included in this PR:

• Editing start/end dates
• Editing trip titles
• Adding more story places after a trip has been created from the story activity
• Edit/delete "photo" media items