[smuxi/stable] (15 commits) ...Engine-Twitter: handle IOException inner-exceptions

[Mirco M. M. Bauer <mmmbauer src gnome org>]

Summary of changes:

  9f41294... Frontend-GNOME: workaround startup crash on Mac OS X with n (*)
  9b5fd1c... Frontend-GNOME: fix open log buttons being sensitive after  (*)
  0513b9c... travisCI: from old trusty(14.04) to xenial(16.04) (*)
  3a54664... travisCI: remove MCS=dmcs hack (*)
  fb19376... travisCI: replace mono 4.6.1 with 4.6.2 (*)
  f04942c... Merge pull request #277 from knocte/patch-2 (*)
  44ab327... configure.ac: should check for NUnit (*)
  660515c... travis: use `set -e` as a workaround for travis not abortin (*)
  6508f97... travis: install libnunit-cil-dev manually to fix build with (*)
  e9951f5... Merge pull request #281 from knocte/fixCiBuildWithNewMono (*)
  d532a47... Build: use NUnit 2.6.1 via Nuget in Visual Studio project f
  d759705... Travis-CI: add Mono versions of current Debian stable Ubunt
  5459e58... Travis-CI: remove Mono 5.18 from versions to fix build
  e046441... Frontend-GNOME: fix method not found exception on Win32
  e079e7b... Engine-Twitter: handle IOException inner-exceptions

(*) This commit already existed in another branch; no separate mail sent