Descriptions should be seen during migration

[d4rky-pl]

(Issue #24 is related to this)

Right now descriptions are only for labeling purposes because it's pretty inconvenient to look into classes comment every time you want to see something was done.

I propose:

1. Showing descriptions of migrations that has been run (let's limit this to, for example 10 at max), e.g.

   20110623142133 - Creating a simple database for accounts
   20110624184914 - Modifying accounts to keep random hash stored in DB
   20110626154632 - Creating new database to keep user credentials for multiple ways of login (openid, facebook connect etc.)

2. Or / and command db:log working similar to git log, showing N latest migrations (with parameters: --from and --to expecting argument to be migrations' ID)

Considering descriptions are already being kept in database (or not) , it won't need much additional work (I will make necessary changes and send a pull request) and it would benefit working in group (during migrations you would have quick overview of what changed in database).

[samwilson]

Descriptions are now shown when migrations are run. Can this be closed?

The matter of the format of descriptions (#24) still stands, though.