Added support to directly connect also to Microsoft SQL Server database.

Fixed direct connection to always use the same query as of UNION query SQL injection (= one query with multiple columns/entries output).
Minor fixes to Firebird/Access/SQLite connectors to use connector's execute()/fetchall() as wrapper for third-party libraries' methods.
Forced conf.timeout to 10 seconds when directly connecting to database.
Slightly improved regular expression to parse -d parameter.
Added import check for all connectors' third-party libraries.
Code refactoring:
* Moved conf.direct request to direct() function in lib/request/direct.py (code reused where needed).
* Back-delegated to generic connector close() and other methods.

plugins/dbms/postgresql/connector.py

@@ -46,10 +46,7 @@ class Connector(GenericConnector):
     def __init__(self):
         GenericConnector.__init__(self)
 
-    def connect(self, reuse=True):
-        if reuse and self.connector:
-            return
-
+    def connect(self):
         self.initConnection()
 
         try:
@@ -82,11 +79,3 @@ class Connector(GenericConnector):
     def select(self, query):
         self.execute(query)
         return self.fetchall()
-
-    def setCursor(self):
-        self.cursor = self.connector.cursor()
-
-    def close(self):
-        self.cursor.close()
-        self.connector.close()
-        self.closed()