This update for seamonkey fixes the following issues:

seamonkey is added to Leap 15.2:

- https://bugzilla.opensuse.org/show_bug.cgi?id=1185349

update to SeaMonkey 2.53.7.1

* Fix for legacy generators and the deprecated for each statement in
  add-ons and the Add-on SDK bug 1702903.
* Fix for handling of dead keys in text input fields in GTK 3.24.26+
  bug 1701288.
* SeaMonkey 2.53.7.1 uses the same backend as Firefox and contains
  the relevant Firefox 60.8 security fixes.
* SeaMonkey 2.53.7.1 shares most parts of the mail and news code
  with Thunderbird. Please read the Thunderbird 60.0 release notes
  for specific changes and security fixes in this release.
* Additional important security fixes up to Current Firefox 78.8 ESR
  and a few enhancements have been backported. We will continue to
  enhance SeaMonkey security in subsequent 2.53.x beta and release
  versions as fast as we are able to.

update to SeaMonkey 2.53.7

* Remove Flash and NPAPI support bug 1688415.
* Switch packaged extensions to be global bug 1659298.
* Add Insert Forms to Composer bug 1684611.
* Fix an issue with copying to IMAP sent folder and some reference
  count leaks in mailnews bug 1689890.
* Tailing to delay tracker requests and enhance performance has been
  enabled bug 1358060.
* Fix an issue with favorite and recent folders not showing in macOS
  bug 1695869.
* Various security and general platform fixes.
* The ChatZilla source has been integrated into SeaMonkey and no
  longer needs to be checked out separately if you build your own
  release bug 1551033.
* SeaMonkey 2.53.7 uses the same backend as Firefox and contains the
  relevant Firefox 60.8 security fixes.
* SeaMonkey 2.53.7 shares most parts of the mail and news code with
  Thunderbird. Please read the Thunderbird 60.0 release notes for
  specific changes and security fixes in this release.
* Additional important security fixes up to Current Firefox 78.8 ESR
  and a few enhancements have been backported. We will continue to
  enhance SeaMonkey security in subsequent 2.53.x beta and release
  versions as fast as we are able to.
* provide a way to auto-select es-AR locale on any Spanish one but
  es-ES

- restore Chatzilla and DOM Inspector packages disabled in Revision
333; these extensions were long since re-enabled upstream but
apparently we had forgotten to re-enable them in the spec file

update to SeaMonkey 2.53.6

* Improve usability of multiple mailboxes/folders selectionbug
  1600103.
* Add Greek localisation (el).
* Remove more RDF from mailnews code.
* Switch to mozilla as topsrcdir and component for building is
  comm/suite now.
* Rust support is now up to 1.48 and official build is now using
  1.47.0
* Various security and general platform fixes.
* SeaMonkey 2.53.6 uses the same backend as Firefox and contains the
  relevant Firefox 60.8 security fixes.
* SeaMonkey 2.53.6 shares most parts of the mail and news code with
  Thunderbird. Please read the Thunderbird 60.0 release notes for
  specific changes and security fixes in this release.
* Additional important security fixes up to Current Firefox 78.6 ESR
  and a few enhancements have been backported. We will continue to
  enhance SeaMonkey security in subsequent 2.53.x beta and release
  versions as fast as we are able to.
- rewrote spec file to account for SeaMonkey's new build system, including
a new Makefile from Dmitry Butskoy: #1181525#c3
- merged the translations-common and translations-other subpackages into
the main package; it is no longer convenient/consistent to keep these
separate because localizations for the integrated IRC and Calendar
clients are already merged in the source. This also solves #1181525.
- enabled and bundled Calendar (Lightning) extension
- cleaned up spec file to remove conditions targeting long-obsolete
openSUSE versions
- disabled elf-hack on i586 builds, as it was preventing compilation

- add patch to enable builds with Rust >= 1.48 on Tumbleweed
https://bugzilla.mozilla.org/show_bug.cgi?id=1617782#c22

This update was imported from the openSUSE:Leap:15.2:Update update project.