Format + organize imports on Grizzly and extras
Remove WTF import
Disable microsoft.com based tests, see #496
Fix javadoc
Turn AsyncHttpClient into an interface, close #497
Merge branch 'asynchttpclient/master'

Conflicts:
	api/src/main/java/org/asynchttpclient/AsyncHttpClient.java
	api/src/main/java/org/asynchttpclient/SimpleAsyncHttpClient.java
	api/src/test/java/org/asynchttpclient/async/MultipartUploadTest.java
	extras/jdeferred/src/test/java/org/asynchttpclient/extra/AsyncHttpTest.java
	providers/grizzly/src/test/java/org/asynchttpclient/providers/grizzly/GrizzlyProviderUtil.java
	providers/netty/src/test/java/org/asynchttpclient/providers/netty/NettyProviderUtil.java
Committing after merging in from OSS repo to get the AsyncHttpClient interface and DefaultAsyncHttpClient class.