Fixing a few time machine bugs

[riknoll]

Fixes three bugs:

1. If you shared a script and then immediately opened the history, the share wouldn't show up
2. There was a minor text bleeding issue in the header on small screens
3. Sometimes the updateHistory would calculate an extra diff when collapsing history entries: one to check for equality, another to actually push on the stack. I replaced the first one with a simple equality check since that's a much cheaper operation