Appease mandoc -Tlint

Add .Xr to pkg_check-version(1) in packages-specs(7), as pkg_check-version(1)
can be used to verify the ordering of package names.

ok tb@

man pages: add missing commas between subordinate and main clauses

jmc@ dislikes a comma before "then" in a conditional, so leave those
untouched.

ok jmc@

explicitly talk a bit about "informal" specs

Add support for "alpha" suffixes in package versions

We already supported "beta" releases but not "alpha", probably to
discourage people from pushing "alpha-quality" software in the ports
tree.

We

Add support for "alpha" suffixes in package versions

We already supported "beta" releases but not "alpha", probably to
discourage people from pushing "alpha-quality" software in the ports
tree.

We have 30 ports with distfiles matching "alpha", and people just work
around the lack of explicit support for "alpha" releases with mixes of
crafted PKGNAME and REVISION/EPOCH. This looks needlessly complicated
and a bit unfair when compared to GH_COMMIT support.

Pointers from landry@ and sthen@, lgtm landry@, no objection from espie@

show more ...

Clarify the use of EPOCH in ports Makefiles.

Whith lots of help from sthen@, espie@ and jca@

ok espie@ jca@

fixup REGRESS_DEPENDS->TEST_DEPENDS
REGRESS_* idiom died a while ago

OK naddy@ sthen@

zap trailing whitespace;

make some assumptions more explicit, after some confusion...

reuse the pkgpath(7) documentation in a more obvious way

new documentation: pkgpath.7
tweaks by jmc@, krw@ approves.
(to be linked to other pages that will need tweaking)

Add examples for various pkgname versions comparisons (rc,beta,pl,pre..)
ok espie@

document how version work.
okay jmc@
landry has some examples to polish.

tweak previous;

document package-specs

/tmp/cvsaGVL4U

remove trailing whitespace;

document the new simpler way to do specs

tie back to bsd.port.mk, to make REVISION and EPOCH more obvious.

typo;

document new semantics

make the version number stuff mandatory.

Restrict specifications to the parts that actually make sense (in particular,
remove most wildcard support, it's no longer a good idea in true
version number

make the version number stuff mandatory.

Restrict specifications to the parts that actually make sense (in particular,
remove most wildcard support, it's no longer a good idea in true
version number handling), explain about v*, and be more specific about
default package specs (since the fuzzyness in the original description
predates several changes to bsd.port.mk).

Also add version numbers and wildcards where they make sense so the examples
are more complete.

show more ...

Patchlevel starts at p0, not p1. Fix the example.

ok espie@ looks fine to ajacoutot@

convert to new .Dd format;

escape punctuation;
ok deraadt@