Fixes 'focus' problem.

[anselmos]

What this PR fixes
This PR should fix or at least hack the problem with focus attribute not working properly.

Related Issues

This PR should fix problems found at #326 and #371

Versions used for this PR

Using latest version of tmuxp : 1.4.0
tmux version : 2.6
latest release of libtmux: 0.8.0

What the PR changes

This PR comments out usage of set_layout_hook that broke focus attribute.

[anselmos]

@tony PTAL - I hope I did not broke anything with this PR - especially the #309 and #312 .

[codecov-io]

Codecov Report

Merging #371 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #371   +/-   ##
=======================================
  Coverage   75.06%   75.06%           
=======================================
  Files           5        5           
  Lines         794      794           
  Branches      231      231           
=======================================
  Hits          596      596           
  Misses        146      146           
  Partials       52       52

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[tony]

So, it's on the right track. We know that this was introduced in #312 (fix for #309). Unfortunately it wasn't backed by a test, which is why this passed in Travis - it would break all tmux 2.6 releases (and probably later).

The issue with the PR in its current form is we don't want to reintroduce #309's issue.

The good news is we know there's something with the hook fix that causes this focus issue.

We need a way to retain the #312 fix (or something equivalent that fixes #309) and fix focus too.

[anselmos]

Closing as #500 has fixed this problem.