Renames view items for regex matching

Update Welcome content
Updates logo (polish)
Adds scss sorting rules

Adds Configuration section to README

Closes #51, Closes #167, Closes #270

Adds advanced.fileHistoryFollowsRenames setting
Adds commands to set rename following to the GitLens explorer

- Removes mix-tree support
  - Avoids nesting on the current branch
  - Caches basename
  - Replaces folder icons with theme icons
    - Folder icons will now follow the file icon theme used
  - Fixes minor nitpicks

Add folder icon
Implement branch folder
Implement branches.layout config option
Fix branch node ordering in Tree layout
Sort branch folder containing current branch correctly
- Add current getter method to BranchNode
- Implment a recursive findCurrent method on BranchFolderNode
Do not parse invalid branch name as branch folder
Expand current branch folder

Adds patreon links

Adds showWhatsNewAfterUpgrades setting
Removes messages.suppressUpdateNotice
Removes messages.suppressWelcomeNotice

Updates all the screenshots
Updates welcome & settings

Adds settings for GitLens Results view
Adds layout settings for explorers
Adds not equals support
Updates README (wip)

Adds a static "container"
Adds a document tracker - replaces the context tracker
Adds a line tracker
Refactors all the things - better performance, lower overhead, less code, more separation of concerns, more maintainable (hopefully)
Changes dirty blame to only happen after a "idle" delay
Closes open file annotations on edit (too expensive to track changes)

Adds Merge Branch (via Terminal) command
Adds Rebase (Interactive) Branch (via Terminal) command
Adds Cherry Pick Commit (via Terminal) command
Adds Revert Commit (via Terminal) command
Adds Create Tag (via Terminal)... command
Adds Delete Tag (via Terminal) command

Adds Compare with Working command

Adds file-based search options to placeholder text

Adds gitlens.explorers.compareWithRemote command

Fixes issues with commit paging in certain quick pick menus

Fixes broken links

Adds Show in Results to file history quick pick
Adds re-query support to GitLog
Fixes Open in File/Revision for file history quick pick

Adds comparison results view