Update packaging for 4.0.0-dev

apache2-utils is no longer a requirement
patch files updated
fixed debian/rules to not delete files that don't exist
More modifications for DOMjudge 4.0.0

htpasswd is no longer used
judgehosts do not connect directly to the database anymore, so dbconfig
for them is no longer needed
change initial sql data to not include examples, and to include the new
defaultdata for files(executables)
Use debconf for configuring a judgehost

The DOMjudge server api details should be asked by debconf
Remove conflicting directory from domserver package
Add build dependencies
Install apache configuration

Set up apache in the postinst step
Add patch to use apache 2.4 instead of 2.2 configuration settings
Update packaging

Update documentation
Change dependencies
Fix permissions on install
Create required users
restapi.secret should only come with the judgehost

This avoids packaging conflicts
Fix error in postinst script
Tweaks to make the packaging better

Update docs to give more details for swapaccount=1
Make init script setup the cgroups as required
Make init script check for swapaccount=1 and that the chroot has been
created
Do not remove the external libraries from the domjudge-domserver package
Change build dependencies

flexc++/bisonc++ are only needed for make dist
libjsoncpp-dev is required for the submitclient
We have to make docs to install them
Remove unnecessary dependencies

Also changed username for the database user
Update patches
Fix packaging conflict

Make rules file more readable
Move files into domjudge-common so there is no conflict between
domserver/judgehost anymore
Merge branch 'master' of https://github.com/domjudge/domjudge-packaging into 4.0-update

Conflicts:
	debian/patches/020_debian_database.php.patch