Windows: NPSupport Remote Name verification

Windows: NPSupport Remote Name verification

When adding a connection verify that the server name and the share name
are valid.  If not return ERROR_BAD_NETWORK_NAME.

When getting connection information, if a pre-existing connection does
not exist and either the server name or the share name do not verify
return ERROR_BAD_NETWORK_NAME and not ERROR_INVALID_PARAMETER.

Change-Id: Ib40a6b56318793d1c1b351ba895736beb616585d
Reviewed-on: http://gerrit.openafs.org/11916
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>