Report waiting processes with a special color and the type of the event they are waiting for #93

For PostgreSQL 9.6, the wait events collect much more types of waits than a heavyweight locks used in the prior versions. We could report them to the user, as well as highlighting such backends with a color that is different from the one used by 'locked' processes nowadays (i.e. report 'locked' processes with red, report waiting processes that are not 'locked' in another color, together with the wait type).

Alternatively, we could report everything as 'locked' (and highlight in red), together with adding the event event.