Revert "Use any instead of anyref for an attributes map"

Save API changes for 2.2.x.

This reverts commit eca1ad2e449593d74213c0ffbbb434c8b8764b5c.
Bump to SBT 0.12.1.
Remove deprecated Scala Tools repo.

Was only needed for 2.8.2, which is no longer supported.
Name the default servlet "default".  Fixes #248.