Closes #410 - adds ability to search by multiple criteria
Adds ability to match case, match all, & use regex

Adds last commit date to branches

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

Reworks generator types

Changes stash[Apply|Delete|Save] commands to use new git commands

Adds explicit directive for going back
Adds command error logging
Removes unneeded abort error

Adds arbitrary ref support to cherry-pick git command
Enhances the feedback when choosing an arbitrary ref

Consolidates more reusable logic into GitService

Changes upstream arrows

Fixes quickpick commands that open the working file

Neither of these cases worked with renamed files

Fixes diff w/ previous when there are no working file changes
Fixes broken status file commands

Removes getRecentLogCommitForFile

Adds GitService.getWorkingUri
Removes WorkspaceFileExistsRequestType from vsls protocol

Removes "Branch or Tag" from all commands
Changes openFileRevisionFrom allow entering references
Fixes missing views.compare.selectForCompare from command palette

Remembers and restores the last commit search string
Adds search command to the results inline toolbar
Reopens search when clicking on a result node with no results
Fixes encoded html in empty state

Updates README (wip)
Updates welcome & settings pages (wip)

Renames showCommitInResults to showCommitInView
Renames showFileHistoryInResults to showFileHistoryInView