Resolved few issues (with some improvements) with existing nodes.

This commit takes care of the following issues/improvements.
* Adding missing imports for unauthorised in database module
* Node under Servers Nodes (i.e. Databases, tablespaces, roles nodes)
  need to be inherited from PGChildNodeView (and, not from NodeView) for
  adding server version check for their children.
* Adding statistics for database, and tablespaces in its node (not, yet
  in UI)
* Renaming the camel case methods with proper name.
  (i.e. getSQL -> get_sql, getNewSQL -> get_new_sql, etc.)
* Fixed the functions going beyond the text limit (column: 80) in
  Databases, Roles & Tablespaces modules.
* Fixed the node method of Database module, which was not tested ever.
* We do not need separate SQL template for fetching the name (i.e.
  get_name.sql), using the 'nodes.sql' for the same.
* Optimise the query for fetching ACLs for the database node, we didn't
  require to join certain tables, while fetching only the ACLs.
* Introduced the list of the ACLs (regular and default ACLs for
  different type) supported by each version [Databases Module].
* Renamed the templates 'get_nodes.sql' to' nodes.sql' to make it
  consistent with other modules.
* Removed the checks for the authentication table use, as we don't need
  to expose the password to the users (even the encrypted MD5). Using
  the pg_roles view always for fetching roles/users information now.
* Resolved some typos in unreachable (specially the exceptions
  catchment area.)
* Logging the exception in the application.
* Using qtLiteral, qtIdent properly in the templates (do not assume
  about the types of data.)
* Using tsid as identifier instead of did for the tablespaces.
* Using nodes method of tablespace view for fetching individual node
  information.
* Removing the hardcoded node information from the 'parse_priv_to_db'
  function, and pass on allowed ACLs by the caller nodes.
* Using 'nodes.sql' to fetch name of the template instead of writing
  that in the delete.sql template, which is definitely wrong place to
  fetch the name of the object. [Tablespace Module]

web/pgadmin/utils/driver/psycopg2/__init__.py

@@ -19,7 +19,7 @@ from flask.ext.security import current_user
 
 from ..abstract import BaseDriver, BaseConnection
 from pgadmin.settings.settings_model import Server, User
-from pgadmin.utils.crypto import encrypt, decrypt
+from pgadmin.utils.crypto import decrypt
 import random
 
 from .keywords import ScanKeyword
@@ -453,7 +453,7 @@ Attempt to reconnect it failed with the below error:
             pg_conn = psycopg2.connect(
                     host=mgr.host,
                     port=mgr.port,
-                    database=db,
+                    database=self.db,
                     user=mgr.user,
                     password=password
                     )
@@ -912,6 +912,7 @@ class Driver(BaseDriver):
             if type(val) == list:
                 return map(lambda w: Driver.qtIdent(conn, w), val)
 
+            val = str(val)
             if len(val) == 0:
                 continue