[SPARK-14795][SQL] Remove the use of Hive's variable substitution

[rxin]

What changes were proposed in this pull request?

This patch builds on #12556 and completely removes the use of Hive's variable substitution.

How was this patch tested?

Covered by existing tests.

[yhuai]

c878aef looks good

[SparkQA]

Test build #56490 has finished for PR 12561 at commit c878aef.

• This patch fails Spark unit tests.
• This patch merges cleanly.
• This patch adds the following public classes (experimental):
  • class HiveSqlParser(conf: SQLConf) extends AbstractSqlParser

[SparkQA]

Test build #2841 has finished for PR 12561 at commit 8864f2a.

• This patch fails Spark unit tests.
• This patch merges cleanly.
• This patch adds no public classes.

[SparkQA]

Test build #56507 has finished for PR 12561 at commit 8864f2a.

• This patch fails Spark unit tests.
• This patch merges cleanly.
• This patch adds no public classes.

[SparkQA]

Test build #56504 has finished for PR 12561 at commit 737ea41.

• This patch fails Spark unit tests.
• This patch does not merge cleanly.
• This patch adds no public classes.

[yhuai]

LGTM

[rxin]

Merging in master.

[SparkQA]

Test build #56555 has finished for PR 12561 at commit f74b381.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.