Add support for virtual hostnames.

Sometimes I can't change the hostname, despite it being on my
network and having `root`.  For those cases, I'll make the virtual
hostname match DNS, at least.

A future improvement might be to get this from reverse DNS?

tcshrc.system.common

@@ -147,6 +147,14 @@ if( $?CSHENV_DEBUG ) then
 	echo "Hostname detected as ${CSHENV_HOSTNAME}..."
 endif
 
+if( $?CSHENV_VIRTUAL_HOSTNAME ) then
+	setenv CSHENV_HOSTNAME ${CSHENV_VIRTUAL_HOSTNAME}
+	if( $?CSHENV_DEBUG ) then
+		echo "Hostname overriden as ${CSHENV_HOSTNAME}..."
+	endif
+endif
+
+
 if( $?CSHENV_DEBUG ) then
 	echo "Done sourcing tcshrc.system.common"
 endif