Exclude Lucene's own JAR files from classpath entries in Eclipse config

[uschindler]

This PR fixes the Eclipse task to exclude Lucene's own JAR files. I think this problem was introduced when we switched to module system, previously the project dependencies were just directories with class files, now it is lucene's JAR files.

This PR is a bit hacky, it applies regex to filename. @dweiss: If you have a better idea how to exclude project dependencies, tell me.

[uschindler]

The reason for this fix is to remove:

• compile problems (sometimes it complains about duplicate class files). This also leads to problems when some aleady compiled code does not get recompiled due to the fact that it cannot see the change (as it refers to JAR instead of Eclipse's project output). This brings strange errors.
• when you open a type it always brings multiple matches (one in JAR file and the other one in source tree). This is anoying

[dweiss]

I'll take a look later today, Uwe.

[dweiss]

Hi Uwe. This looks fine for me. Ideally, this should scan the dependencies and exclude project dependency artifacts (this is possible) but it adds a whole lot of code and achieves pretty much the same effect. I don't think the complexity is worth the gain here, as mentioned in the comment.

            // This is hacky - we take the resolved compile classpath and just
            // include JAR files from there. We should probably make it smarter
            // by looking at real dependencies. But then: this Eclipse configuration
            // doesn't really separate sources anyway so why bother.
            jars += prj.configurations.compileClasspath.resolve()
            jars += prj.configurations.testCompileClasspath.resolve()