Merge pull request #245 from carryel/master

About redundant timeout exception of Grizzly provider (Issue #244)
Port MiscUtil.isNonEmpty to master
Port fix for #139 to master
Port fix for #239 to master
Re-enable PropertiesBasedResumableProcesserTest, close #53
Minor clean up
Optimize and clean up NettyFuture.done, close #141
Mention that RequestBuilder is mutable and not threadsafe, close #238
Refactor NettyAsyncHttpProviderConfig, make non Netty properties explicit members, close #164
Expose HttpClientCodec params in NettyAsyncHttpProviderConfig, partial fix for #162
Port #250 to master, close #202
When using a proxy, Netty provider should send relative urls once connected, not absolute ones, fix #251
Rollback #251
Fix the connection channel issue at proxy mode
Merge pull request #252 from suenway/master

Patch for inappropriate connection channel when working at proxy mode
Add getURI method on ProxyServer, close #253
Introduce useRelativeURIsWithSSLProxies, close #236, close #251
Reduce URI creation in fix #115
Set Connection header as close when connection pooling is disabled, partial fix for #254

Grizzly provider fails on
GrizzlyBasicAuthTest.basicAuthFileNoKeepAliveTest
[Fix] HMAC-SHA1 key was not correctly encoding according to specs http://oauth.net/core/1.0/#anchor16