editors/emacs: Update to 27.1

[jrm]

Summary

This contains the final 27.1 release and is ready for review.
Port changes:

• depend on math/gmp
• match upstream by turning CAIRO, HARFBUZZ, and JSON options on and turning MAGICK off by default
• remove OPENMP check for graphics/ImageMagick as the openmp is now included in base
• update EMACS_VER in Mk/Uses/emacs.mk
• bump USES=emacs ports or remove BROKEN for net-im/jabber.el and deskutils/howm, which now build

TODO: Possibly wait for Yuuji to re-test and rename the canna patch from emacs27.0.90-canna-20200308.diff.gz to emacs27.1-canna-202008xx.diff.gz.

Test Plan

• testport 11/12 i386/amd64 all flavors
• test with devel/llvm10 which is shipped in -STABLE, and -CURRENT platforms

[jrm]

deskutils/howm also builds now

[jrm]

Update canna patches for 27.0.90

Submitted by: HIROSE Yuuji <[e-mail]>

[jrm]

• editors/emacs: WIP for 27.1; Update to version 27.0.91

[jrm]

rc1 is out

[jrm]

• editors/emacs WIP: Update to rc2
• editors/emacs WIP: Fix a few issues related to rebase WIP branch on top of master branch

[jrm]

• Re-remove BROKEN from deskutils/howm and net-im/jabber.el

[jrm]

Update to the 27.1 release

[jrm]

Add UPDATING entry and squash all WIP commits

[ashish]

I think we should fix the UPDATING.

UPDATING

17 ↗

(On Diff #75683)

[jrm]

• Fix UPDATING entry

[jrm]

• Fix UPDATING entry (take 2)

[jrm]

Re-bump PORTREVISIONS losts with git rebase master

[jrm]

More PORTREVISION changes

[jrm]

• Tweak UPDATING message and add not for portmaster users.

[jrm]

Committed.