First Work on trackers to generate events

Only Issue events are created for now
Stop updating objects with old data
Get events in the reverse order (oldest first)

Importe to create our own events in the right order
Create events parts event for create events
Simple text/html rending for events
Correct mergeable status of new PRs
Manage display of big list of modified files
Shortcuts to navigate between files & comments on files tab

n/j to go to next file
p/k to go to previous file
shift + [n/j] to go to next comment
shift + [p/k] to go to previous comment
Make toggle detail/group on issues list work on the current list

And enhance the toggle-detail action to correctly manage the opened
groups height
Use "f" to focus the filter box in files view

And also
- replace the use of "s" by the use of "f" to focus the filter box in
issues list
- use the SHIFT modifier to change tabs (with d/c/f) on a pull request
Use "t" on pr files list to toggle the files list summary
Add a colored top border for active panel