[SPARK-2615] [SQL] Add Equal Sign "==" Support for HiveQl

Currently, the "==" in HiveQL expression will cause exception thrown, this patch will fix it.

Author: Cheng Hao <hao.cheng@intel.com>

Closes #1522 from chenghao-intel/equal and squashes the following commits:

f62a0ff [Cheng Hao] Add == Support for HiveQl
Graphx example

fix examples

Author: CrazyJvm <crazyjvm@gmail.com>

Closes #1523 from CrazyJvm/graphx-example and squashes the following commits:

663457a [CrazyJvm] outDegrees does not take parameters
7cfff1d [CrazyJvm] fix example for joinVertices
[YARN][SPARK-2606]:In some cases,the spark UI pages display incorrect

The issue is caused by #1112 .

Author: GuoQiang Li <witgo@qq.com>

Closes #1501 from witgo/webui_style and squashes the following commits:

4b34998 [GuoQiang Li] In some cases, pages display incorrect in WebUI