Remove $FreeBSD$: one-line sh pattern

Remove /^\s*#[#!]?\s*\$FreeBSD\$.*$\n/

Performance and debugging enhancements:
+ Remove UNAME_P=$(...) from startup/misc -- already supplied by common.subr
+ Use f_getvar instead of $(eval echo \$$var) -- f_getvar is sub-shell free
+ Add `-e' and `-k var' options to f_eval_catch -- increasing use-cases
+ Use f_eval_catch to display errors on failure -- reducing duplicated code
+ Use f_eval_catch when we need output from a command -- improving debugging
+ Optimize f_isinter of strings.subr for performance -- now sub-shell free
+ Improve error checking on pidfiles -- using f_eval_catch and f_isinteger
+ Use $var_to_set arg of f_ifconfig_{inet,netmask} -- eliminate sub-shells
+ Use f_sprintf instead of $(printf ...) -- consolidate sub-shells
+ Use $var_to_set arg of f_route_get_default -- eliminate sub-shells
+ Add f_count to replace $(set -- ...;echo $#) -- eliminate sub-shells
+ Add f_count_ifs to replace $(IFS=x;set -- ...;echo $#) -- no sub-shells
+ Replace var="$var${var:+ }..." in loops with var="$var ..." with a follow-
up var="${var# }" to trim leading whitespace -- optimize loops
+ Use $var_to_set arg of f_resolv_conf_nameservers -- eliminate sub-shells
+ Comments for the f_eval_catch function
+ Remove a duplicate `local ... desc ...' in f_device_get_all of device.subr
+ Use $var_to_set arg of f_device_capacity -- eliminate sub-shells
+ Whitespace fixes in f_dialog_init of dialog.subr
+ Optimize f_inet_atoi of media/tcpip.subr for performance -- sub-shell free
+ In several cases, send stderr to /dev/null -- clean up runtime execution
+ Change f_err of common.subr to go to program stderr not terminal stderr,
allowing redirection of output from functions that use f_err
+ Disable debugging when using f_getvar to get variable argument to
f_startup_rcconf_map_expand of startup/rcconf.subr
+ Use f_replace_all instead of $(echo ... | tr | sed) -- performance
+ Add a $var_to_set option to f_index_{file,menusel_{command,keyword}} of
common.subr -- centralize sub-shells

Always shutdown the media when we're exiting the packages module (prevents
errors on re-entry for physical media). Also, while we're here, stop
ejecting the CDROM when we're done with it (but leave the functions for
later use so that we could perhaps -- from the installer standpoint -- use
it to eject the media after an install).

MFC after: 3 days

Fix typos in the BSD License.

Be consistent with other usr.sbin programs w/respect to the copyright
wording ("All rights reserved."); I had the casing wrong on many instances.

More whitespace.

Comments.

Centralize standard getopts arguments, both for convenience and to correct
a bug in which certain combinations of arguments produced unexpected results
such as `-dX' (now properly produces debugging and X11), `-XS' (now properly
produces X11 in secure mode), `-df-' (enables debugging when reading a
script from standard-input, etc. Multi-word variations such as `-d -X',
`-X -S', `-d -f-', `-d -f -', etc. also work as expected. Also tested were
variations in argument order, which are now working as expected.

Commit first portion of package module -- this includes the ability to view
categories, view packages, mark packages for installation, de-installation,
or re-installation, calculate and track dependencies, as well as ability to
review selections.

Still to come is the actual processing of selections (performing the
various actions associated with the user's selections, such as installing
dependencies first, then selections, etc.).