- get rid of PHP warning during mass import that $activities->nextPageToken is
  undefined
- during mass all import, always request 100 items per page
- remove legacy duplicate check via last_activity_id
- only include parameters in G+ API call, which are actually set


git-svn-id: https://plugins.svn.wordpress.org/g-crossposting/trunk@996346 b8457f37-d9ea-0310-8a92-e5e31aec5664