pgAdmin III commit: Refactor the listview population code and optimise

Refactor the listview population code and optimise in a number of
ways:
- Only load data into listviews that are currently visible, or are
  about to become visible.
- Avoid loading statistics, dependencies and dependents twice(!)
  every time the current object selection changes.
- Centralise the refresh and reset code.

Branch
------
master

Details
-------
http://git.postgresql.org/gitweb?p=pgadmin3.git;a=commitdiff;h=00892aab45144a4a068ead9d00871e534c7a4770

Modified Files
--------------
pgadmin/frm/events.cpp        |   29 ++++++++++++++++-----
pgadmin/frm/frmMain.cpp       |   57 +++++++++++++++++++++++++++-------------
pgadmin/include/frm/frmMain.h |    4 ++-
pgadmin/schema/pgObject.cpp   |   19 +-------------
4 files changed, 64 insertions(+), 45 deletions(-)