Fix for oracle not supporting generatedkeys method

Used a select query after inserting a queue to DB to get the queue id.
This is to avoid subtle differences in different DB vendors jdbc driver
in returning generated key for queue id.
Adhere to coding standards.
Merge pull request #229 from akalankapagoda/reviewFixes

Adhere to coding standards.
Merge pull request #231 from indikasampath2000/performance

sendMessageToFlusher method changed in MessageFlusher
Implement channel flow control
Merge pull request #232 from a5anka/publisher_flow_control_with_disruptor

Implement publisher flow control
second time subscription null pointer exception fixed
Merge pull request #233 from sajinidesilva/serilizer-bugs

Second time subscription null pointer exception fixed
Merge pull request #234 from Asitha/oracle-issue

Fix for oracle not supporting generatedkeys method
Add missing imports
Merge pull request #235 from a5anka/flow_control

Add missing imports
RDBMS related class names renamed.

- Class names and package name of RDBMS specific classes changed from
  JDBC prefix to RDBMS prefix
RDBMS store table names updated
Merge pull request #237 from Asitha/RDBMS-schema-update

Rdbms schema update
Add Global limit flow control
Add documentation for Flow control related code.
fix missing import
Merge pull request #238 from Asitha/missing-imports

Fix missing import
Add configuration error handling and some refactoring suggested in the code review.
Merge pull request #236 from a5anka/publisher_flow_control_with_disruptor

Publisher flow control with global buffer limit