Fix table cellpadding

galaxql.cpp

- (Galaxql::OnRunqueryClick)
Remove the cellpadding attribute from the query result table. The
default wxHtmlWindow cellpadding will be used as a result.

wxWidgets seems to have some problem with small cellpadding values:
'wxHtmlWindow table problem when cellpadding < 3'
http://trac.wxwidgets.org/ticket/16586
Change destroy db confirmation to default to No

- (Galaxql::OnResetAllClick)
Make No the default button when requesting user confirmation to reset
everything (ie destroy the database).