Remove $FreeBSD$: one-line sh pattern

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

Fix typo in r312216

I meant to replace "exp" with "exponent", not "expected"

MFC after: 13 days
Pointyhat to: ngie
Submitted by: bde

Revert r312119 and reword the intent to fix -Wshadow issues
between exp(3) and `exp` var.

The approach taken previously was not ideal for multiple
functional and stylistic reasons.

Add to existing sed call in Makefile to replace `exp` with
`exponent` instead.

MFC after: 13 days
Requested by: bde

Merge ^/user/ngie/release-pkg-fix-tests to unbreak how test files are installed
after r298107

Summary of changes:

- Replace all instances of FILES/TESTS with ${PACKAGE}FILES. This ensures that
namespacing is kept with FILES appropriately, and that this shouldn't need
to be repeated if the namespace changes -- only the definition of PACKAGE
needs to be changed
- Allow PACKAGE to be overridden by callers instead of forcing it to always be
`tests`. In the event we get to the point where things can be split up
enough in the base system, it would make more sense to group the tests
with the blocks they're a part of, e.g. byacc with byacc-tests, etc
- Remove PACKAGE definitions where possible, i.e. where FILES wasn't used
previously.
- Remove unnecessary TESTSPACKAGE definitions; this has been elided into
bsd.tests.mk
- Remove unnecessary BINDIRs used previously with ${PACKAGE}FILES;
${PACKAGE}FILESDIR is now automatically defined in bsd.test.mk.
- Fix installation of files under data/ subdirectories in lib/libc/tests/hash
and lib/libc/tests/net/getaddrinfo
- Remove unnecessary .include <bsd.own.mk>s (some opportunistic cleanup)

Document the proposed changes in share/examples/tests/tests/... via examples
so it's clear that ${PACKAGES}FILES is the suggested way forward in terms of
replacing FILES. share/mk/bsd.README didn't seem like the appropriate method
of communicating that info.

MFC after: never probably
X-MFC with: r298107
PR: 209114
Relnotes: yes
Tested with: buildworld, installworld, checkworld; buildworld, packageworld
Sponsored by: EMC / Isilon Storage Division

More 'tests' package fixes.

Sponsored by: The FreeBSD Foundation

Avoid requiring 'make depend' here.

Really this should not be a DPSRCS. The acct_test.c should not #include
convert.c, but just link it in as a normal SRCS.

MFC after: 1 week
Sponsored by: EMC / Isilon Storage Division

Fix up convert.c generation

- Use a temporary file for convert.c to reduce likelihood of an interrupted
build resulting in bad code being written to convert.c
- Truncate the file instead of appending to it to ensure that the file being
touched will not result in duplicate declarations/definitions from
kern_acct.c if/when kern_acct.c changes.

MFC after: 1 week

Integrate acct(2) testcase in as tests/sys/kern/acct/acct_test

The :encode_tv_random_million testcase fails the epsilon tests a few thousand
times out of one million, so expect the testcase to fail

MFC after: 1 week
Submitted by: keramida
Sponsored by: EMC / Isilon Storage Division