[SQL][DOC][Minor] Spark SQL Hive now support dynamic partitioning

Author: wangfei <wangfei1@huawei.com>

Closes #3127 from scwf/patch-9 and squashes the following commits:

e39a560 [wangfei] now support dynamic partitioning
[SPARK-4225][SQL] Resorts to SparkContext.version to inspect Spark version

This PR resorts to `SparkContext.version` rather than META-INF/MANIFEST.MF in the assembly jar to inspect Spark version. Currently, when built with Maven, the MANIFEST.MF file in the assembly jar is incorrectly replaced by Guava 15.0 MANIFEST.MF, probably because of the assembly/shading tricks.

Another related PR is #3103, which tries to fix the MANIFEST issue.

Author: Cheng Lian <lian@databricks.com>

Closes #3105 from liancheng/spark-4225 and squashes the following commits:

d9585e1 [Cheng Lian] Resorts to SparkContext.version to inspect Spark version
[SQL] Support ScalaReflection of schema in different universes

Author: Michael Armbrust <michael@databricks.com>

Closes #3096 from marmbrus/reflectionContext and squashes the following commits:

adc221f [Michael Armbrust] Support ScalaReflection of schema in different universes
[SQL] Modify keyword val location according to ordering

'DOUBLE' should be moved before 'ELSE' according to the ordering convension

Author: Jacky Li <jacky.likun@gmail.com>

Closes #3080 from jackylk/patch-5 and squashes the following commits:

3c11df7 [Jacky Li] [SQL] Modify keyword val location according to ordering