Milestone version, ready for production environment

major improvement:

• Resolved the issue that HPL/SQL can not select Date and Timestamp type values into variables
• Resolved the issue that HPL/SQL incorrectly generate literal when referring Date or Timestamp type variable in SELECT or other SQL statements, eg. it should be DATE '2019-02-20', not 2019-02-20 .

Improved scalability and resolved incorrect keyword TABLE for INSERT INTO statement

• improve scalability, under 10 seconds initial time with 1000+ stored procedures in Vertica on physical machine.
• new test framework, testSuite.sh and genResult.sh, to generate test out file of queries and run test cases.
• resolved issue #1 "INSERT INTO TABLE ERROR". Thanks for bug report from @HongJunDW.

Better performance, and support negative forms of variables

Sub-task

• cache parsed PL/SQL tree for better performance
• rename UDF PLSQL_ADD to PLSQL_CREATE
• add test scripts for Standalone and In Vertica mode
• synchronized from upstream, HIVE-21308: Negative forms of variables are not supported in HPL/SQL

Integrate HPLSQL of hive to Vertica

Sub-task:

• Integrate HPLSQL of hive to Vertica
• Provide two deploy modes - Standalone mode and In Vertica mode