Move webtasks to ae.sys.d.customizer
ae.sys.d.customize: Refactoring
Refactoring
web: Page switching refactoring
Reimplement digger "build" action using DCustomizer
Allow merging arbitrary GitHub forks
web: Refactor pull request list to generic expandable nestable sections
Add base selection to web interface
Add browsable forks to web UI
web: Focus "Continue" button by default
bisect: Fix bisect
bisect: Log revision resolution
ae.sys.d.customizer: Remove fork remotes after they're no longer needed

Avoids fetching them every time.
web: Reinstate "Everything" button