Source of proxy info (descending priority)
- GUI RPC (Manager or boinccmd)
This and only this is saved in state file.
If neither HTTP nor SOCKS server name present,
this is viewed as not present
- environment vars
- cc_config.xml
Show sources of proxy info in message log.
If one is present but overridden, show a message to that effect.
This fixes a bug where someone had a proxy info env var and
forgot about it.
They got an erroneous message saying no proxy was being used.
svn path=/trunk/boinc/; revision=19785