Merge remote-tracking branch 'pjf/nunit_gui_tests' into release-v1.2

* pjf/nunit_gui_tests:
  Travis: Start xvfb for GUI tests.
Merge remote-tracking branch 'mgsdk/certificate-fix' into release-v1.2

* mgsdk/certificate-fix:
  Show error message for missing certificate in the GUI.
  Catch authentication error with https.
Merge remote-tracking branch 'RichardLake/DisplayExecptionInfo' into release-v1.2

* RichardLake/DisplayExecptionInfo:
  Fixed format string in GUI/Program.cs Now the GUI will display a some information in the case of unhandled exceptions. May help with bug reports.
Fix mod list column resize on first repo update

(cherry picked from commit b9a411bb2e9d8bd249df4f930554733e40a26acb)
Merge remote-tracking branch 'nlight/505_dialog_size' into release-v1.2

* nlight/505_dialog_size:
  Small fix to get our changes after InitializeComponent();
  Fix #505
GUI stuff, check description

- Better wrapping for the mod description
- Mark all updated button now greyed out if no updates are available

(cherry picked from commit 51eb519a6499189b5eb45096a1809caf35beae80)
Better display of provided modules

(cherry picked from commit e52577c6f778a7917a6344c172d06b11158e5f78)
Add a CKAN icon.

For #240.

This doesn't seem to be giving me joy under Linux, but Linux may well
ignore embedded icons. Going to seek test on IRC now.
Merge remote-tracking branch 'upstream/240_icon' into 240_icon
Transparent icons, larger range of sizes.

Closes #240.
Merge remote-tracking branch 'upstream/240_icon' into 240_icon
trimmed icon