Error messages

[brutasse]

Hi guys,

I'm getting started with Nashvegas and ran into a couple of minor issues:

• running the upgradedb --seed command prints a traceback, I changed it to a friendlier error message and added a note in the doc stelling people to use an argument.
• the doc says migration scripts need to start with a number but upgradedb breaks if I use "001-initial-tables.sql" - it expects an underscore as a separator, I changed it to use a regexp instead so that any separator is allowed.

Feel free to pull if you're interested :)

[paltman]

thanks! i'll check these out today.

[paltman]

these are merged into master!