Mention setting :sign-releases false during deploy.
Attempt to force Aether to re-check for new versions of templates.

According to preliminary reports on IRC there may be issues where
Aether ignores this directive, but it's best to set it anyway since it
may be fixed in future versions.
Rearrange .gitignore and remove windows line endings.
Discuss idempotency of hooks/middleware in plugin docs.
Encourage production use of uberjars over `lein run` in tutorial.