Makes them conditional on state

Even if the active line didn't change

Giving up on better else/catch/finally formatting -- can't fight anymore
Switching to tabs for better accessibility
https://twitter.com/sh4na/status/1146837957200027648

Disables commands for the deleted or missing sha
Adds getNextDiffUris & getNextUri
Renames getDiffWithPreviousForFile to getPreviousDiffUris
Renames getPreviousRevisionUri to getPreviousUri

Adds hovers.changesDiff setting for line vs hunk diff

Keeps all path manipulation on the host rather than guest
Fixes shared/local path munging for mac/windows
Keeps current user lookup local when a guest
Keeps difftool lookup local when a guest
Avoids fetch date lookup when a guest
Stops clearing node_modules (for now)

Fixes auto-refresh context on repositories view loading

Changes line history to use GitLineTracker for better resource usage

Removes Uri monkey patch as it no longer will work
See 03432806c8
Stops encoding uris in .toString calls

Less roundtrips through to the UI on changes for better performance/UX
Also adds "flash" protection to deal with the active editor changing to undefined between changes

Closes #209 - Open File in Remote should ask for a branch if no upstream

When current line blame starts off, the toggle doesn't work

Splits currentLineController into:
lineAnnotationController - end of line annotation
lineHoverController - hovers to current line(s)
statusBarController - blame on the statusbar

Fixes open file, open revision, & show file history

Adds a new "missing" document to allow the tracker to track these files