AuthentiCode sign launcher, uninstaller

[tresf]

Refactors NSIS installers and ANT to provide properly sign .exe files:

• Centralizes and consolidates ant signing code to signing.xml
• Adds signing steps for uninstall.exe, qz-tray.exe
• Removes NSIS built-in "Uninstall" section, uses masqueraded "Install" instead
• Changes all ant messages from default warning level to info level.
• Renamed apple codesigning targets to avoid confusion

Closes #593

[tresf]

Tested on Windows XP, Windows 7, Windows 10. All pass. In doing so, found some lingering launcher that weren't be cleaned up properly 5e4624e, f2655ff.

[tresf]

Tested on Ubuntu 18.04, passes.

Tested on MacOS 10.15 and it fails with the following message on the HTTP about page:

java.lang.NoClassDefFoundError: jssc/SerialNativeInterface
	at qz.common.SecurityInfo.getLibVersions(Unknown Source)
	at qz.common.AboutInfo.libraries(Unknown Source)
	at qz.common.AboutInfo.gatherAbout(Unknown Source)
	at qz.ws.HttpAboutServlet.generateHtmlResponse(Unknown Source)
	at qz.ws.HttpAboutServlet.doGet(Unknown Source)
        ...

I suspect something's gone wrong with the mac code signing steps.

[tresf]

I suspect something's gone wrong with the mac code signing steps.

Fixed via 59f0f7a. Tested macOS 10.8, 10.15, passing.

Final step is checking if notarization passes, then we can merge.