client: actually print error from server when upload fails

Change-Id: I98236bc4e6680e0a3d89f2a1a1c47b77ef90e0a0
Merge "client: actually print error from server when upload fails"
Move GCE stuff out of camlistored into new package. Use from camtool.

Now camtool dumpconfig works on GCE too using the same mechanisms as camlistored.

Change-Id: I11c5311a6b7ace35fb0c6dd661ba9bdcad7820ed
Merge branch 'master' of https://camlistore.googlesource.com/camlistore