Make sure to read socket in BINARY buffer

This bug caused broken response content in ruby 2.0 + chunked encoding +
multibyte response. Fixes #171. Thanks for finding this!

Change of default file encoding in ruby 2.0 makes ''.encoding to UTF-8
instead of BINARY.
Version bump to 2.3.4
Remove a test accessing non-existing-host

Can't remember the intent of this test.
Respect 1.8.7

2.3.4 broke 1.8.7.  Even though 1.8.7 is sunsetted there's no need to
break existing application with 1.8.7
Add PATCH method functionality
Add tests for patch and patch_async
Merge remote-tracking branch 'nick/master'

Conflicts:
	httpclient.gemspec
	lib/httpclient.rb
	lib/httpclient/session.rb
	lib/httpclient/version.rb
	test/test_httpclient.rb