Disable autosave as it's causing issues.

For example it causes duplicate parts to be created if autosave triggers
between adding a part, and doing a full save.
Merge pull request #121 from alphagov/disable_autosave

Disable autosave as it's causing issues.
Actually remove autosave functionality.

Pending tests were causing the Jenkins build to be flagged unstable.
Let's actually remove this as opposed to just disabling it.  We can
always find it in git if it's needed.
Merge pull request #122 from alphagov/disable_autosave

Actually remove autosave functionality.