Facebook iOS SDK 3.6

Summary:
     see https://developers.facebook.com/ios/change-log-3.x/

    Upgrading from 3.5
     https://developers.facebook.com/docs/tutorial/iossdk/upgrading-from-3.5-to-3.6

Reviewed By: jacl

Test Plan: Release Testing.
Facebook iOS SDK 3.7

Summary:
     see https://developers.facebook.com/ios/change-log-3.x/

    Upgrading from 3.6
     https://developers.facebook.com/docs/tutorial/iossdk/upgrading-from-3.6-to-3.7

Reviewed By: jacl

Test Plan: Release Testing.
Merge branch 'facebook-sdk-master'

Conflicts:
	samples/FriendPickerSample/FriendPickerSample.xcodeproj/project.pbxproj
	samples/FriendPickerSample/FriendPickerSample/FPAppDelegate.m
	samples/GraphApiSample/GraphApiSample.xcodeproj/project.pbxproj
	samples/GraphApiSample/GraphApiSample/GraphApiAppDelegate.m
	samples/HelloFacebookSample/HelloFacebookSample.xcodeproj/project.pbxproj
	samples/HelloFacebookSample/HelloFacebookSample/HFAppDelegate.m
	samples/HelloFacebookSample/HelloFacebookSample/HFViewController.m
	samples/PlacePickerSample/PlacePickerSample.xcodeproj/project.pbxproj
	samples/PlacePickerSample/PlacePickerSample/PPAppDelegate.m
	samples/ProfilePictureSample/ProfilePictureSample.xcodeproj/project.pbxproj
	samples/ProfilePictureSample/ProfilePictureSample/PPAppDelegate.m
	samples/RPSSample/RPSSample.xcodeproj/project.pbxproj
	samples/RPSSample/RPSSample/RPSAppDelegate.m
	samples/RPSSample/RPSSample/RPSFriendsViewController.m
	samples/RPSSample/RPSSample/RPSSample-Info.plist
	samples/Scrumptious/ReadMe.txt
	samples/Scrumptious/Scrumptious.xcodeproj/project.pbxproj
	samples/Scrumptious/scrumptious/SCAppDelegate.h
	samples/Scrumptious/scrumptious/SCAppDelegate.m
	samples/Scrumptious/scrumptious/SCLoginViewController.h
	samples/Scrumptious/scrumptious/SCLoginViewController.m
	samples/Scrumptious/scrumptious/SCLoginViewController.xib
	samples/Scrumptious/scrumptious/SCViewController.h
	samples/Scrumptious/scrumptious/SCViewController.m
	samples/Scrumptious/scrumptious/scrumptious-Info.plist
	samples/SessionLoginSample/SessionLoginSample.xcodeproj/project.pbxproj
	samples/SessionLoginSample/SessionLoginSample/SLAppDelegate.m
	samples/SwitchUserSample/SwitchUserSample.xcodeproj/project.pbxproj
	samples/SwitchUserSample/SwitchUserSample/SUAppDelegate.m
	samples/SwitchUserSample/SwitchUserSample/SUUserManager.m