Enhancements from our first migration.

Enhancements from our first migration.

* Make MediaWiki regex more lenient with trailing newlines
* Add check to see if application is configured; if it isn't
  bail out and don't migrate.
* Perform increments early enough so that numeric IDs are unique
* Fix bug in increment printing
* fdopen() doesn't work, so simply create a blank lockfile
* Make force removal log message more descriptive
* Remove .scripts/old-version code
* Prefer git describe method, but if it doesn't work switch
  to .scripts-version
* Make shell return appropriate values during dry runs
* Make call error more descriptive (this messes with exception
  counting, however.)

Signed-off-by: Edward Z. Yang <ezyang@mit.edu>