Added option to ignore folders without style definitions during theme compilation

[edler-san]

Relates to #7848

This problem still persists in Vaadin 8.7.2 and applies to Subversion, CVS, Dimensions and probably others.
I added the ignoreNonThemeFolders option to the vaadin-maven-plugin and created PRs in vaadin/maven-plugin and vaadin/sass-compiler.
(vaadin/maven-plugin#116 and vaadin/sass-compiler#321)

With this option set to true the plugin looks for styles.scss in all folders under src/main/webapp/VAADIN/themes and will ignore failures due to folders created by versioning systems that do not contain a style definition. Information about failed attempts is printed to the console.

You can use it via

  <configuration>
        <ignoreNonThemeFolders>true</ignoreNonThemeFolders>
   </configuration>

in the vaadin-maven-plugin

[stale]

Hello there!

We are sorry that this issue hasn't progressed lately. We are prioritizing issues by severity and the number of customers we expect are experiencing this and haven't gotten around to fix this issue yet.

There are a couple of things you could help to get things rolling on this issue (this is an automated message, so expect that some of these are already in use):

• Check if the issue is still valid for the latest version. There are dozens of duplicates in our issue tracker, so it is possible that the issue is already tackled. If it appears to be fixed, close the issue, otherwise report to the issue that it is still valid.
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• Add a reduced test case about the issue, so it is easier for somebody to start working on a solution.
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• If the issue is clearly a bug, use the Warranty in your Vaadin subscription to raise its priority.

Thanks again for your contributions! Even though we haven't been able to get this issue fixed, we hope you to report your findings and enhancement ideas in the future too!