newvers.sh: add support for gitup(1)

[michael-o]

gitup writes a .gituprevision file into the shallow clone directory. Read that
file and print commit plus branch information along with other version information.

[michael-o]

@emaste Here it is. Please have a look. This is how it looks for me:

# uname -a
FreeBSD bsd1srv.fritz.box 12.2-STABLE FreeBSD 12.2-STABLE 25e00a289 (stable/12) GENERIC  amd64
$ uname -a
FreeBSD bsd1srv.fritz.box 12.2-STABLE FreeBSD 12.2-STABLE 1c002413c ((detached)) GENERIC  amd64
$ uname -a
FreeBSD bsd1srv.fritz.box 12.2-STABLE FreeBSD 12.2-STABLE 6a45b9926 (stable/12) GENERIC  amd64

This is an upport to current. I use stable/12. I'd appreciate a backport to 12.

[michael-o]

Bug Id: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=252507

[emaste]

I'm currently blocked on johnmehr/gitup#36 for testing

[emaste]

#36 is now fixed

@uqs your take?

[emaste]

Here's what a stable/12 .gituprevision looks like in my tree

$ hexdump -Cv .gituprevision 
00000000  73 74 61 62 6c 65 2f 31  32 3a 62 37 39 31 62 35  |stable/12:b791b5|
00000010  37 36 33                                          |763|
00000013

[michael-o]

Everything has been merged. Thanks!

[markmi]

The git branch information is not redundant in my context of use and my local git branches now put the lines back in after the lines were removed from FreeBSD's main. (This does not deal with the lack of redundancy for pure FreeBSD branches in my context, unfortunately.)

[michael-o]

The git branch information is not redundant in my context of use and my local git branches now put the lines back in after the lines were removed from FreeBSD's main. (This does not deal with the lack of redundancy for pure FreeBSD branches in my context, unfortunately.)

I advocated to have them, but committers thought otherwise.

[michael-o]

The git branch information is not redundant in my context of use and my local git branches now put the lines back in after the lines were removed from FreeBSD's main. (This does not deal with the lack of redundancy for pure FreeBSD branches in my context, unfortunately.)

I would also like to point out that I created two distinct commits with proper messages. They were needlessly squashed into one.