Implement remaining API calls in hangups.Client

[tdryer]

hangups.Client should implement methods to access every API call. Implement the remaining ones to complete this list:

• [X] clients/setactiveclient
• [ ] contacts/dismisssuggestedcontacts
• [X] contacts/getentitybyid
• [ ] contacts/getfavorites
• [X] conversations/getgroupconversationurl
• [X] contacts/getselfinfo
• [x] contacts/getsuggestedentities
• [X] contacts/searchentities
• [ ] contacts/setcalleridconfig
• [ ] contacts/setconfigurationbit
• [ ] contacts/undismisssuggestedcontacts
• [ ] contacts/updatefavoritecontact
• [X] conversations/adduser
• [X] conversations/createconversation
• [ ] conversations/declineallinvites
• [X] conversations/deleteconversation
• [X] conversations/easteregg
• [X] conversations/getconversation
• [ ] conversations/getoffnetworkinviteurl
• [ ] conversations/markeventobserved
• [ ] conversations/modifyconversationview
• [ ] conversations/modifyotrstatus
• [X] conversations/removeuser
• [X] conversations/renameconversation
• [ ] conversations/reportabuseconversation
• [ ] conversations/replytoinvite
• [X] conversations/sendchatmessage
• [x] conversations/setconversationnotificationlevel
• [X] conversations/setfocus
• [X] conversations/setgrouplinksharingenabled
• [X] conversations/settyping
• [X] conversations/syncallnewevents
• [X] conversations/syncrecentconversations
• [ ] conversations/updateinvitationwatermark
• [X] conversations/updatewatermark
• [ ] devices/finishphonenumberverification
• [ ] devices/registerdevice
• [x] devices/sendoffnetworkinvitation
• [ ] devices/startphonenumberverification
• [X] presence/querypresence
• [X] presence/setpresence
• [ ] presence/setrichpresenceenabledstate

To be completed after #140.

[avaidyam]

Looks like there are additional ones used in the Android app.

hangouts/add
hangout_invitations/ack
handoffnumbers/update
hangout_participants/search
handoffnumbers/add
hangouts/resolve

[tdryer]

Updated list based on Hangouts web:

• [X] adduser
• [X] createconversation
• [ ] declineallinvites
• [X] deleteconversation
• [ ] dismisssuggestedcontacts
• [X] easteregg
• [X] getconversation
• [ ] getfavorites
• [X] getgroupconversationurl
• [ ] getinvitesettings
• [ ] markeventobserved
• [ ] modifyconversationview
• [X] modifyotrstatus
• [X] querypresence
• [X] removeuser
• [X] renameconversation
• [ ] replytoinvite
• [X] sendchatmessage
• [X] sendoffnetworkinvitation
• [X] setactiveclient
• [ ] setconfigurationbit
• [X] setconversationnotificationlevel
• [X] setfocus
• [X] setgrouplinksharingenabled
• [ ] setinvitesettings
• [ ] setinvitesettingspreset
• [X] setpresence
• [ ] setrichpresenceenabledstate
• [X] settyping
• [X] syncallnewevents
• [X] syncrecentconversations
• [ ] undismisssuggestedcontacts
• [ ] updatefavoritecontact
• [ ] updateinvitationwatermark
• [X] updatewatermark