copy svn support scripts as-is from our chef deployment scripts
replace occurences of 'redmine' with 'openproject'
add back --redmine-host option for compatibility

because we don't want to break old OpenProject installations.
However, this options is deprecated.
We need libapache2-svn for a working svn setup
re-integrate repository_authentication plugin
fix failing specs
Merge pull request #1623 from opf/backport/1615

Backport/1615