Tools update support

[hohwille]

With devon ide update it should be possible to update the entire devon-ide.
Thus if the project lead defines a tool version in devon.properties inside the settings Git repo and updates it (e.g. VSCODE_VERSION=1.99.1) then the above command should be able to also update according tools (e.g. vscode) to that version (and reinstall all plugins).

This is however challenging. Many of the tools we support have a bad or inconsistent version and release management:

• Some tools do not offer a way to query the current version (fine is mvn -v or java -version however the output might be tricky to parse, but vscode or eclipse do not support a commandline option for this).
• Some tools have download URLs that do not easily correlate to the release number. Hence magic knowledge is required to figure out the download URL from the version and OS (see e.g. issue Update VS Code to 1.33.1 #109)

For the first point we could easily write a devon-tool-version.properties file into the software/«tool» folder as a workaround (at least for tools that do not support a proper way to determine the installed version).
The second point is even more tricky. IMHO we could only resolve this with either of the following options:

• the user has to provide more information (VSCODE_VERSION=1.99.1 would not be enough but also VSCODE_HASH=51b0b28134d51361cf996d2f0a1c698247aeabd8 and VSCODE_REV=1554971043) - however, these values are tricky to figure out and users will be lost in space
• we provide a kind of mapping to get the details from the version and maintain that for every version. However, we would need to continuously provide updates of this and VS Code changes quickly. So I assume we are unable to keep the pace and would end up as blocker
• we maintain the mapping separate from devon-ide releases and provide it as separate online configuration download or service. Maintenance could be supported by the entire community so the first user needing the new version would do the work (done in 5 Minutes if you know what to do, we could provide a guide)
• we fully automate this and follow redirects, etc.
• we get in touch with the makers of the tools and ask for improving their downloads
• we redistribute the software in a systematic way

[hohwille]

For VSCode there are links that redirect to the according hash. E.g.:

• https://update.code.visualstudio.com/1.33.1/win32-x64-user/stable
• https://update.code.visualstudio.com/1.33.1/darwin/stable
• https://update.code.visualstudio.com/1.33.1/linux-x64/stable

[hohwille]

more or less done with PR #114
However, currently you need to rerundevon ide setup.
So only devon ide update needs to be slightly modified to complete this.
Please also note that some tools like e.g. jenkins do not support this new approach and also need to be updated.

[hohwille]

Just created #140 for the remaining todos so we can close this issue.