Fixes and optimizations in ContainerFilter

ContainerChainedFilter:

• optimization - no need to continue filtering if logis is AND or ANDNOT and result is empty

ContainerFilterBean:

• add STARTS_WITH comparator
• instead of JahiaConsole use logger
• use of PreparedStatement

FilterClause:

• add check for IS_NULL and NOT_NULL clauses
• add STARTS_WITH comparator
• bug in COMP_NOTNULL comparator - use && instead of ||

In all files:

• optimize getting current timestamp
• fix some compiler warnings