Rename models.File to models.Note across the application

[sethwoodworth]

Do this in all:

• variable
• class
• function names
• docstrings and comments
• user-facing text

[CharlesHolbrow]

Stackoverflow post with a good way to do this:

http://stackoverflow.com/a/2899145

[CharlesHolbrow]

We will need to manually modify the schema migration. Models with ForeinKey(Note) or ForeignKey('Note') members will need to be included.

class Vote(models.model) has
note = models.ForeignKey(File)

class ReputationEvent(models.model) has
file = models.ForeignKey(File, blank=True, null=True)

class UserProfile(models.model) has
files = models.ManyToManyField(File, blank=True, null=True)

[sethwoodworth]

This is very close to complete. There are a few function names that refer to file that need to be reworked, but that can happen when we restructure to class-based views. I'm not going to check this off until we test the refactor branch.