top: highlight all regular search string(s) when found

top: highlight all regular search string(s) when found

With the recent inspect search highlight provisions in
place, the lack of highlighting in task based searches
has grown from being only irritating to a real defect.

Thus, this commit introduces parallel functionality to
those searches initiated within a visible task window.
And just as separate inspect searches are possible for
each selection, per window task searches are provided.

However, it should be noted that there are differences
between task based searches and inspect type searches:

* There is no concept of out-of-view data when dealing
. with task rows -- if the data can't bee seen, it has
. not, in fact, been constructed from a proc_t struct.

* While inspect data is output at the character level,
. up to now all task display data was only potentially
. output and it was always based on a complete string.

* With task search highlighting, rows now containing a
. match must be output in pieces and, therefore, can't
. be optimized away like other rows which haven't been
. been altered. This is because top cannot predict the
. the contents of a search string or, how many matches
. might occur in a given row. Short search strings and
. many matches would raise buffer needs geometrically.

(now that we know a '.' + 2 spaces is squeezed to one)
(everything's perfectly justified, but it's just luck)

Signed-off-by: Jim Warner <james.warner@comcast.net>