auth storage

[gimsieke]

Instead of supplying username and password on the command line when invoking a pipeline, we would like to use the invoking Linux user’s cached authentication info if available, for example in /home/wbdvwork/.subversion. So if username and password are missing, the steps should look at some default locations before raising an error.
org.tmatesoft.svn.core.internal.wc.DefaultSVNAuthenticationManager should be able to do these lookups.

[mkraetke]

Sounds reasonable to me, I can implement this feature.