Summary:
This change adds <swiftInstall>/bin to the library lookup paths.
Without, QFactoryLoader is not able to find the Qt plugins
on Mac OS since on this platform the hard coded path defaults to
'foo.app/Contents/MacOS' for app bundles.
This change also adds the installation of QtPrintSupport framework which
is a dependency from cocoa platform plugin.
ref T48
Reviewers: kbasan, msutcliffe
Reviewed By: kbasan
Subscribers: jenkins
Maniphest Tasks: T48
Differential Revision: https://dev.swift-project.org/D15
Sample hotkey which requires access to CGuiApplication, did not yet
set a application role. Since there was no corresponding role for
samples, I added one and set it in sample hotkey.
