It has been a while since all pages have moved to json instead of form
data, except for login page. This commit changes login to json data
instead of form one
* Allow to use single web instance for any repository
* some improvements
* drop includes from user home directory, introduce new variables to docker
The old solution didn't actually work as expected, because devtools
configuration belongs to filesystem (as well as sudo one), so it was
still required to run setup command.
In order to handle additional repositories, the POSTSETUP and PRESETUP
commands variables have been introduced. FAQ has been updated as well
* raise 404 in case if repository is unknown
