switch to sockets.tcp for the socket provider

Tested with 'grunt integration', which verifies that basic tcp functionality works.
Note that manifests of chrome apps using this version will need to change per https://developer.chrome.com/apps/app_network
-15 is SOCKET_NOT_CONNECTED in chrome (http://src.chromium.org/svn/trunk/src/net/base/net_error_list.h).  I think removeActive may be correct, so far I haven't seen any error that didn't completely disconnect my socket.  So if its true that for all read errors, the socket is disconnected, it seems like freedom should clean up the listeners.