Merge pull request #8 from SeeD-Seifer/master

Throw WebException if no internet connection
Bump OkHttp version
Merge remote-tracking branch 'origin/master'
Version bump to 0.9
Add license
No cancellation for you
Samples and Xamarin Component resources for xam generation.

Minor changes to the main Makefile so an alternate MDTOOL can be specified and
to avoid the clean target from failing.

Also, the component review guidelines prefer that the API revision 9 is targeted
for Android libraries and samples.
Knock down OkHttp's required SDK nonsense
Merge remote-tracking branch 'origin/pr/9'
Added the xamarin-component binary, to simplify setup.
Implement manual cancellation on Android
Close streams when we're done
Ignore build products
Add a playground project
Make sure we build our vendor DLL even in Release
Fix a crash where we'd end up doing network requests on the UI thread
More ConfigureAwait(false)s
Rewrite to handle returning headers early
Add an explicit cancel button to playground
Clean up code and add note about Mono bug