Fixed: 0001133: exported files contain only the SELECT statement
Fixed: 0001130: further mssql issues with ` not recognised

The problem is that MSSQL don't recognize as field marker it uses [ and ] so I defined two global variables $FieldMarkerLeft and $FieldMarkerRight that are seted in the common.php file. This variables should replace the we use.

git-svn-id: file:///Users/Shitiz/Downloads/lssvn/source/limesurvey@3153 b72ed6b6-b9f8-46b5-92b4-906544132732