MacOS download (4.2.1) doesn't contain a version number

[suschizu]

Describe the bug
The macOS binary download doesn't contain any version number (its empty)
(https://github.com/xaos-project/XaoS/releases/download/release-4.2.1/XaoS-4.2.1.dmg)

the BundleVersion and ShortVersionString keys are missing in the info.plist
should look like that:

	<key>CFBundleShortVersionString</key>
	<string>4.9.15</string>
…
	<key>CFBundleVersion</key>
	<string>4.9.15</string>

Desktop (please complete the following information):

• Version 4.2.1

[kovzol]

Thanks for your bug report! The .dmg file is automatically created by the macdeployqt application from Qt, we don't add or change anything after it finishes. Maybe it has an issue you encountered.

[kovzol]

Hm, this seems helpful: http://www.edenwaith.com/blog/index.php?p=125

[vitorgalvao]

The seems to be a problem in general when building Qt apps.

See #223 for a way to add the version numbers after the app is built (simple enough that it could be added to the built script).