Event/epoch history explorer

[heralden]

Thanks for the immensely useful dev tool!

I think we can make it even better! Something I miss from a similar tool (Redux dev tools) is an overview/history of all events/epochs, allowing you to scroll through them and jump to a specific one.

I created a MVP that fulfills the above description, but I'd like to get some feedback on it and some ideas I have to improve it, which I'll work on next week.

It's hidden by default and is toggled with the up/down arrow below the skip-to-last button (which I made smaller and pushed up).

Here's the stuff on my list:

• Fix alignment and sizes of skip-to-last and toggle button
• Save open/close state to local storage so it can be restored (not sure if this is worth doing as I imagine the history explorer would generally be used to jump between a few epochs, then close it once done)
• Fix first event init-db not being shown as active when selected (differing id?)
• Perhaps different font color for future events when any other than the most recent event is selected, to indicate that these haven't happened yet
• Try to make the simple css resize handle prettier not possible in firefox, and it looks fine in chrome/webkit
• If possible, simplify the :epochs/all-indexed-events sub (name could be improved as well?)
• Test with long events to make sure they create ellipses

Update: I'm pretty happy with how things are now, so I'll wait for feedback for now.

[superstructor]

Thanks for this awesome contribution @uosl and apologies for taking as long as we have to merge it!

Due to conflicts recently introduced on master I pulled your feature/event-history branch locally, rebased on master and merged.

It will be released as 0.4.4 soon.

[heralden]

Thanks for merging! And no worries, I know handling open source contributions can be a lot of work.