Start working on timer for workout and log while in the gym, refs #49
Add a simple countdown graph with canvas
Update changelog
Merge
Some cosmetic changes to timer page
Move logic for determining the timer steps from template to view
Generate more correct 'pages' for timer template
Add method to generate a canonical representation of a workout

This representation can be used everywhere where a workout or parts of
it are processed or otherwise shown to the user and is easier to cache.
Add view to enter a single workout weight log

This view is reached from the timer view to add the individual weight
entries via AJAX.
Start the countdown after leaving an exercise step
Add progress bar to the timer pages to check exercises left to do
Cleanup and refactor JS countdown code, make +/- buttons functional
Calculate the total workout time when reaching the last page
Cleanup CSS code and other cosmetic changes
Merge
Some changes to gym mode to make it work with jQueryMobile 1.4