Build js class for handle build page behaviour

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Refactor build page logic

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Redirect to page with build id if missing

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Escape build output

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Changelog and version 4.3.0.pre

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
 Merge branch 'refactor/build_js' into 'master'

Refactor: Build page