Delay zooming on resize a little bit in gviz to prevent hogging CPU.
Reduce delay a little bit.
Import shlex from the beginning
Merge branch 'experimental' of github.com:kliment/Printrun into experimental
Remove "pessimistic" from estimated duration string

The computed duration is no more pessimistic, for a few reasons.
- the main one is that it does not take retraction into account
- Z moves are not taken into account either
- arcs are not supported
- the acceleration code seems to estimate acceleration time correctly but is
  wrong for deceleration
So instead of telling the user this estimation is pessimistic, let's just tell
them this is an estimate.