[SPARK-5741][SQL] Support the path contains comma in HiveContext

When run ```select * from nzhang_part where hr = 'file,';```, it throws exception ```java.lang.IllegalArgumentException: Can not create a Path from an empty string```
. Because the path of hdfs contains comma, and FileInputFormat.setInputPaths will split path by comma.

### SQL
```
set hive.merge.mapfiles=true;
set hive.merge.mapredfiles=true;
set hive.input.format=org.apache.hadoop.hive.ql.io.HiveInputFormat;
set hive.exec.dynamic.partition=true;
set hive.exec.dynamic.partition.mode=nonstrict;

create table nzhang_part like srcpart;

insert overwrite table nzhang_part partition (ds='2010-08-15', hr) select key, value, hr from srcpart where ds='2008-04-08';

insert overwrite table nzhang_part partition (ds='2010-08-15', hr=11) select key, value from srcpart where ds='2008-04-08';

insert overwrite table nzhang_part partition (ds='2010-08-15', hr)
select * from (
select key, value, hr from srcpart where ds='2008-04-08'
union all
select '1' as key, '1' as value, 'file,' as hr from src limit 1) s;

select * from nzhang_part where hr = 'file,';
```

### Error Log
```
15/02/10 14:33:16 ERROR SparkSQLDriver: Failed in [select * from nzhang_part where hr = 'file,']
java.lang.IllegalArgumentException: Can not create a Path from an empty string
at org.apache.hadoop.fs.Path.checkPathArg(Path.java:127)
at org.apache.hadoop.fs.Path.<init>(Path.java:135)
at org.apache.hadoop.util.StringUtils.stringToPath(StringUtils.java:241)
at org.apache.hadoop.mapred.FileInputFormat.setInputPaths(FileInputFormat.java:400)
at org.apache.spark.sql.hive.HadoopTableReader$.initializeLocalJobConfFunc(TableReader.scala:251)
at org.apache.spark.sql.hive.HadoopTableReader$$anonfun$11.apply(TableReader.scala:229)
at org.apache.spark.sql.hive.HadoopTableReader$$anonfun$11.apply(TableReader.scala:229)
at org.apache.spark.rdd.HadoopRDD$$anonfun$getJobConf$6.apply(HadoopRDD.scala:172)
at org.apache.spark.rdd.HadoopRDD$$anonfun$getJobConf$6.apply(HadoopRDD.scala:172)
at scala.Option.map(Option.scala:145)
at org.apache.spark.rdd.HadoopRDD.getJobConf(HadoopRDD.scala:172)
at org.apache.spark.rdd.HadoopRDD.getPartitions(HadoopRDD.scala:196)

Author: q00251598 <qiyadong@huawei.com>

Closes #4532 from watermen/SPARK-5741 and squashes the following commits:

9758ab1 [q00251598] fix bug
1db1a1c [q00251598] use setInputPaths(Job job, Path... inputPaths)
b788a72 [q00251598] change FileInputFormat.setInputPaths to jobConf.set and add test suite

sql/hive/compatibility/src/test/scala/org/apache/spark/sql/hive/execution/HiveCompatibilitySuite.scala

@@ -632,6 +632,7 @@ class HiveCompatibilitySuite extends HiveQueryFileTest with BeforeAndAfter {
     "mapreduce8",
     "merge1",
     "merge2",
+    "merge4",
     "mergejoins",
     "multiMapJoin1",
     "multiMapJoin2",

sql/hive/src/main/scala/org/apache/spark/sql/hive/TableReader.scala

@@ -248,7 +248,7 @@ private[hive] object HadoopTableReader extends HiveInspectors {
    * instantiate a HadoopRDD.
    */
   def initializeLocalJobConfFunc(path: String, tableDesc: TableDesc)(jobConf: JobConf) {
-    FileInputFormat.setInputPaths(jobConf, path)
+    FileInputFormat.setInputPaths(jobConf, Seq[Path](new Path(path)): _*)
     if (tableDesc != null) {
       PlanUtils.configureInputJobPropertiesForStorageHandler(tableDesc)
       Utilities.copyTableJobPropertiesToConf(tableDesc, jobConf)

sql/hive/src/test/resources/golden/merge4-0-b12e5c70d6d29757471b900b6160fa8a

@@ -0,0 +1 @@
+0

sql/hive/src/test/resources/golden/merge4-1-593999fae618b6b38322bc9ae4e0c027

@@ -0,0 +1 @@
+0

sql/hive/src/test/resources/golden/merge4-14-ba5dbcd0527b8ddab284bc322255bfc7

@@ -0,0 +1,3 @@
+ds=2010-08-15/hr=11
+ds=2010-08-15/hr=12
+ds=2010-08-15/hr=file,

sql/hive/src/test/resources/golden/merge4-15-68f50dc2ad6ff803a372bdd88dd8e19a

@@ -0,0 +1 @@
+1	1	2010-08-15	file,

sql/hive/src/test/resources/golden/merge4-2-43d53504df013e6b35f81811138a167a

@@ -0,0 +1 @@
+0

sql/hive/src/test/resources/golden/merge4-3-a4fb8359a2179ec70777aad6366071b7

@@ -0,0 +1 @@
+0

sql/hive/src/test/resources/golden/merge4-4-16367c381d4b189b3640c92511244bfe

@@ -0,0 +1 @@
+0