expose: Better error formatting and generic flag message

Re error formatting:
$ osc expose svc frontend --port=5432 --generator='service/v2' --name=test

Before:
error: generator %!!(MISSING)q(<nil>) not found.
see 'osc expose -h' for help.

Now:
error: generator "services/v2" not found.
see 'openshift cli expose -h' for help.

docs/kubectl_expose.md

@@ -37,7 +37,7 @@ $ kubectl expose rc streamer --port=4100 --protocol=udp --name=video-stream
       --generator="service/v1": The name of the API generator to use.  Default is 'service/v1'.
   -h, --help=false: help for expose
   -l, --labels="": Labels to apply to the service created by this call.
-      --name="": The name for the newly created service.
+      --name="": The name for the newly created object.
       --no-headers=false: When using the default output, don't print headers.
   -o, --output="": Output format. One of: json|yaml|template|templatefile.
       --output-version="": Output the formatted object with the given version (default api-version).
@@ -83,6 +83,6 @@ $ kubectl expose rc streamer --port=4100 --protocol=udp --name=video-stream
 ### SEE ALSO
 * [kubectl](kubectl.md)	 - kubectl controls the Kubernetes cluster manager
 
-###### Auto generated by spf13/cobra at 2015-05-21 10:33:11.197790185 +0000 UTC
+###### Auto generated by spf13/cobra at 2015-06-02 11:05:52.857144556 +0000 UTC
 
 [![Analytics](https://kubernetes-site.appspot.com/UA-36037335-10/GitHub/docs/kubectl_expose.md?pixel)]()

docs/man/man1/kubectl-expose.1

@@ -48,7 +48,7 @@ re\-use the labels from the resource it exposes.
 
 .PP
 \fB\-\-name\fP=""
-    The name for the newly created service.
+    The name for the newly created object.
 
 .PP
 \fB\-\-no\-headers\fP=false