Don't mess up drop-downs out of the breadcrumbs
Docs: Make switch virtualenv instructions more prominent

Converted instructions to switch the virtualenv on and off to a note with
examples. This way is more difficult to miss it.
Docs: Remove unnecessary paragraph from hacking docs

I forgot to remove it when dropping the instructions for impatient people.
Docs: Add tagging support to changelog
Docs: Provide docs for goals
Add info about extension actions
Docs: update TM doc for local TM
Docs: added Evernote changelog and differences wrt upstream