Added photo example
added iOS send message code
added send message Android code
Merge pull request #825 from aogilvie/feature/messaging

Feature/messaging
Updated documentation
Update TROUBLESHOOTING.md
Update TROUBLESHOOTING.md
added browser platform compatibility and sample app
simplified javascript api file path
moved javascript api file
updated platform javascript api files to match browser api file
fixed correct image path in README
Merge pull request #840 from aogilvie/feature/browser-platform

Feature/browser platform
Share Dialog does not require Login or any extended permissions

Currently user have to have an active session with Facebook plugin to use **"Share Dialog"**, but Facebook documentation suggest *". This does not require Facebook Login or any extended permissions, so it is the easiest way to enable sharing on web."*

This Change just request an active session when developer execute a showDialog different than a share dialog
Share Dialog does not require Login or any extended permissions

If is a Share dialog but FB app is not installed the WebDialog Builder fails. In Android all WebDialogs require a not null Session object.

Documentation for Android SDK FeedDialog:
https://developers.facebook.com/docs/reference/android/3.0/class/WebDialog.FeedDialogBuilder/

**session** The Session representing an authenticating user to use for showing the dialog; must not be null, and must be opened.
Merge pull request #851 from jcvalerio/patch-2

Share Dialog does not require Login or any extended permissions
Added native share dialog
Merge pull request #856 from aogilvie/no-login-share

Added native share dialog
Update README.md
simple update of iOS SDK to 3.21.1