Added json support for PostgreSQL
Pseudo fixed an issue with debug limit by raising the limit
Ignored ide files

Copied empty backend skeleton to db2 backend

Added DB2 detection and building

Implemented session backend calls
Added DB2 backend
Added better error message for describe column
Added string bulk operations test
Made connect string compatible with ODBC connect string
Made connect string compatible with ODBC connect string
Fixed invalid autocommit setting
Turned autocommit to on by default
Fixed invalid parameters binding
Added statement unbinding before statement handle cleanup
Ignored ide files

Copied empty backend skeleton to db2 backend

Added DB2 detection and building

Implemented session backend calls
Added DB2 backend
Removed x_unsigned_log from the db2 backend.
Fixed libdir detection for db2
fixed sqlite3 test
Merge remote-tracking branch 'snikulov/fix_for_15' into issue-15
Merge remote-tracking branch 'upstream/master' into issue-15
Update to Sergei Nikulov's fix for issue #15

Clarify supported sequence of statement::execute(false|true) and
statement::get_affected_rows() calls across all backends:
1. execute(false) and empty destination does not execute statement, but
prepares for subsequent statement::fetch() requests.
2. execute(true)  and empty destination calls requests backend to
execute statement.
3. execute(false|true) causes bulk fetch to destination, with
withDataExchange=false|true ignored.
Moved relevant test to common tests, confirmed it passes for all but
Oracle (get_affected_rows not implemented) and Firebird (I have no means
to test).
Related discussion at
http://sourceforge.net/mailarchive/message.php?msg_id=30312517
Thanks to Sergei who first proposed this behaviour as reliable and
consistent option, yet not intrusive.