[SQL] SPARK-4700: Add HTTP protocol spark thrift server

Add HTTP protocol support and test cases to spark thrift server, so users can deploy thrift server in both TCP and http mode. 
The documentation can be built with Jekyll. You need RubyGems installed, then

1. `gem install jekyll` to install jekyll
2. `cd` into `$SPARK_HOME/docs`
3. `jekyll build`