Correctly set TouchCollection.IsConnected based on TouchPanelCapabilities.IsConnected (not that that is correct yet).

Fixes #2531
Windows TouchPanelCapabilities MaximumTouchCount/IsConnected detection.
Android TouchPanelCapabilities MaximumTouchCount/IsConnected detection. These are sort of wrong due to API limitations, 2 means 2-4, 5 means 5+
Tidy up licence and usings in this file
iOS maximumTouchCount support. Harded coded values as found on google.
Linux and Mac have no touch support for now.
Touch count support for windows phone and PSM. PSM is just made up for now.
Since I've touched almost every line in here, white space cleanup.
Revert TouchCollection constructor back to XNA4 spec. TouchCollection.IsConnected now just proxies to TouchPanel.GetCapabilities().IsConnected
Merge pull request #2534 from danzel/touchpanel-isconnected

TouchPanelCapabilities (IsConnected, MaximumTouchCount) for all platforms