Add support for CommonSelectionParameter

There are problems with page size and page loading speed when there
are more routers with several peers and several BGP related commands
because selection commands multiplicate the peer tables in the resulting
javascript placed into the resulting page. This is not effective enough and
therefore sligh rewrite is needed.

Introduce new type of SelectionParameter - CommonSelectionParameter that
has its ID and it is placed to a JS variable in the beginning of the page
or function that uses the values inside only once. Then construction of the
select boxes uses this variables to feed needed values according to the
ID of the content.
Convert Cisco to use CommonSelectionParameter

Convert Cisco routers and commands to use CommonSelectionParameter
instead of SelectionParameter.
Convert BIRD to use CommonSelectionParameter

Convert BIRD router handlers and commands to use CommonSelectionParameter
instead of SelectionParameter.
Fix typos introduced by previous commit

Fix minor typos introduced by previous commit. The bug slightly affected
effectivness of the ULG CGI startup.
Convert Juniper to use CommonSelectionParameter

Convert Juniper router handlers and commands to use CommonSelectionParameter
instead of SelectionParameter.