SQL server boolean expression bug has been resolved.

A CASE WHEN statement has been generated for boolean expressions in SQL
server using BooleanToIntegerCaseExpression in SQLServer vendor class.
Imports for SQL Server Vendor Boolean Bug Resolving Code
Reconnection support to KeepAliveAgent

ConnectedDB.KeepAliveAgent is enhanced to reset the database connection
field of ConnectedDB if it notices that the database connection was
lost.
Merge pull request #181 from tayfunhalac/master

* Fix bug with boolean conditions on SQL Server
* Re-connect JDBC connection after keepAlive query failure