Infrastructure for MDES version migration. #3465.

No actual version migrations are implemented in this commit.
Alphabetize and standardize layout.
A version migration that does the minimum necessary. #3465.
Register a Basic migration for 3.0 to 3.2. #3465.

There are no semantic alterations of values existing in 3.0 going to
3.2.

This commit also makes the default migrations created per-invocation,
allowing them to have context-sensitive options.
Change console output. #3465.

Migrations may have their own output, so single-line cleverness is not
appropriate.
Add MDES 3.2 to list of codes that get created. Done with #3465.

It's not clear to me how the existing 3.2 file was generated without
this.

There were apparently also codes missing from the 3.1 file. This
commit adds those.

#3474 also related to this change.
Merge pull request #57 from NUBIC/3465-mdes30_to_32

A mechanism for defining migrations to perform when changing the MDES version of a deployment, plus the migration for 3.0 to 3.2 (#3465)