New features

Useful keyboard shortcuts for navigation :
- In a scenario with the navigation keys (up, left, down, right).
- To the parent scenario with ctrl + alt + up.
New minimap style (thanks @aklevy).
Readme improvements (thanks @aklevy).
Speed slider : right click allows to set the value precisely, ctrl + right click allows to reset it to 1.0
When playing a single state, it will now briefly flash in green.
Useful keyboard shortcuts (available in View menu) : unroll (ctrl+alt+U) and fold (ctrl+alt+F) all intervals' racks in a scenario.

Bug fixes