bt-check-ui: add docs for the uitest helpers and a env-var

With BT_CHECK_NO_XVFB=1 one can skip Xvfb (for testing). Add doc comment for the
UI test helper.
make: disable accessibility bridge

Supresses a warning, that is not useful in this context anyway.
check-ui: ensure we reset server_pid
tests: make init oder for ui/edit closer to other suites

Add a comment regarding the gdk issue we are seeing right now.
make: fix make dist
tests: also allow to bypass xvfb here
docs: remove unused vars

We don't use tmpl files.
docs: update bt-edit docs

Drop since tags from imported scrolled-sync-window as they don't make sense
anymore. Skip scrolled-sync-window from the docs. Update sections file.
tests: fix srcdir!=builddir issues for shunit tests
dist: make distcehck fixes
docs: typo fixes and comment update
ignore: ignore test log archives