Typo fixes

PR:		ports/163101
Submitted by:	Jason Helfman <jhelfman@experts-exchange.com>
One more typo, bump .Dd
Move 'make clean' to the background. There is no point waiting around
for it to finish. In the case of very large work directories this may
cause some I/O contention during the unpacking of the next port to
build, but in most cases this should be lost in the noise.
Update copyright
Print the same progress update that goes to the term title in-line
Add a test for background clean processes to finish before emptying
directories in WRKDIRPREFIX
Improve error handling for pm_mktemp. For some reason, exit called from
within a function is not actually exiting, so handle this with a little
more brute force.
Add robust error handling for pm_cd_pd, to avoid the problem of exit not
being called from a function.

Fix an error handling fix for pm_mktemp from the previous commit

Speed up the determination of WRKDIRPREFIX
If the second argument to -o is something that is completely non-existent,
properly report what the user typed in the error message.

Reported by:	avilla
Give the (verbose) messages about cleaning up a little whitespace,
and clarify what we are waiting for.
Make the new count variable in parent_exit local
Remove the misguided r236841
Apply a better solution to the pm_mktemp() problem
In iport_from_origin() work around pkg_info returning 0 even if there is
no match

In clean_build_only_list() remove ports that are already installed to
prevent them from being spuriously removed. [1]

Reported by:	avilla [1]
Move the test for installed ports on the build-only dep list to a better
location, after the code that checks to see if any ports on the list are
depended on. Also, we only want to disqualify an installed port if we're
doing --delete-build-only. If the port is already installed and needs an
update, --packages-build still applies.
Give a better error message if pm_mktemp() fails

Add some whitespace after the message about removing empty directories
In multiport(), count the number of ports in worklist_tmp, then use that
for the first progress update. The number might get revised due to the
user opting out of an update that matches a glob pattern, but it's better
than doing 1/1, 2/2, etc. in the first pass.
When calling trap_exit() in a child process we need to signal the
parent(s) that we trap'ed so that the various post-run cleanups and
updates can still happen properly.

In a related change, in safe_exit() remove a shortcut from r214541 that
was safe at the time, but isn't any longer because we now have more
stuff happening after a run so we still need to update the parent even
if the child fail'ed or trap'ed.

When we're run by script(1) the parent process is going to be [sh], not
$0, so go back to the less efficient but safer method of safeguarding
the parent in kill_bad_children().

For -a remove a -v line that is redundant now with the new in-line
term_printf() code.

In the new in-line printing code for term_printf() use a simpler
pattern to match $1 that also catches the following ...

In multiport(), update the total number of ports after the first pass
to account for ports given on the command line that turn out to be
dependencies of other ports given on the command line, and print a
summary with the number of parent ports and dependencies prior to the
confirmation prompt.
Add code to detect dependency loops created by moving part of a port
into another port, and CONFLICT'ing on previous versions of that port
(ala textproc/p5-XML-SAX -> p5-XML-SAX-Base). When a loop is detected
suggest that the user try pkg_updating.
Remove one more too-verbose term_printf from -a