londiste.get_table_list: move complex copy logic away
londiste.get_table_list: move complex copy logic away

It is now in separate function and called only
for 'in-copy' and 'catching-up' tables.

Should make things more maintainable and speed up common case.

markokr/skytools,markokr/skytools,overdrive3000/skytools,tarvip/skytools,overdrive3000/skytools,tarvip/skytools,overdrive3000/skytools,tarvip/skytools,markokr/skytools