pgAdmin III commit: Check for the session (backend) on which the target

Check for the session (backend) on which the target was running, if it does not exist, we wait for another session to
invokethe target. 

Also - resolved couple of other problem related to the debugger:
- On cancellation of progress dialog, it was not closing the debugger.
- In direct debugging, the target was invoked without taking care about quotes.

This patch also includes couple of other issues introduced by the earlier patch.
1. Showing the messages multiple times in the message window (Query window)
2. Cancellation of query wasn't working on Query window.

Branch
------
master

Details
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http://git.postgresql.org/gitweb?p=pgadmin3.git;a=commitdiff;h=d5b4002caf858cdf4d0daad353b5a41bb5cdf197
Author: Ashesh Vashi <ashesh.vashi@enterprisedb.com>

Modified Files
--------------
pgadmin/ctl/ctlSQLResult.cpp             |   23 +++++-
pgadmin/db/pgQueryThread.cpp             |  129 ++++++++++++++++++++++++------
pgadmin/debugger/dbgController.cpp       |    6 ++
pgadmin/debugger/dbgEvents.cpp           |   45 ++++++++++-
pgadmin/debugger/dbgTargetInfo.cpp       |    4 +-
pgadmin/frm/frmQuery.cpp                 |    4 +
pgadmin/include/db/pgQueryThread.h       |    4 +
pgadmin/include/debugger/dbgController.h |    4 +
8 files changed, 187 insertions(+), 32 deletions(-)