Avoid overlong regex line in javascript.

See merge request GNOME/geary!419

Workaround type initialisation deadlock in GObject

See merge request GNOME/geary!407

Application.Controller: Permit notifications when no main window

Closes #716

See merge request GNOME/geary!420

If there's no main window, the app must be running hidden, so
notifications should be sent.

Fixes #716

The regex line in this javascript was > 256 characters, which triggers
the following warning from debian's "lintian" source-checking tool:

    https://lintian.debian.org/tags/source-is-missing.html
    https://lintian.debian.org/tags/source-contains-prebuilt-javascript-object.html

This offers no functional change, but avoids some needless warnings
going forward.

alert dialog: Align checkbutton to start, not end

Closes #714

See merge request GNOME/geary!417

Problem report memory fixes

See merge request GNOME/geary!418

Take a copy of extant log records when constrcuted so that newer records
can be dropped while the problem report still exists. This uses more
memory, but limits unbounded memory growth while any log reports
still exists.

Clear logs iteratively to avoid recursively freeing all log messages on
the stack at once.

Fixes #714.

(cherry picked from commit e05021bcaf21480ecb922851db3dace89cda2ced)

Close composer completion on Esc

See merge request GNOME/geary!416

Addresses comment in #577

Composer context menu emoji

Closes #713

See merge request GNOME/geary!415

Closes #713