Put version-specific apps on server to download

[HBehrens]

Since e847fbf each build replaces the current downloadable zip with the latest result. While this guarantees a stable download URL one cannot access a specific version anymore.

In addition to the simple CamHolderApp.zip there should be a version-specific download that either

• uses the bundle version (e.g. CamHolderApp-0.2.10.zip) or
• the commit hash (e.g. CamHolderApp-e847fbf4b2b150abb41865e2138c527c8f9de606.zip)

to distinguish versions. I tend to use the former although it requires to change the bundle's version number regularly.