exclude .ily from complete compilation and speed up build process

[nittka]

This is a proposed fix for #95. The compile job for .ily files still has to be created in order to remove old markers but I removed all steps I thought to be unnecessary within the job. I sorted the files for compilation so that fast jobs (.ily) are handled first. This keeps the list of open jobs short (progress view).

Previously a new resource set was used for each direct include calculation. Changing that to one common resource set for each build speeds up the process. For the same reason I introduced the set of files for which this calculation has been done already (the filesToBuild-set does not quite serve the same purpose, it does not prevent duplicate calculation). As a result (on my slow Windows machine), the time for calculating allIncludingFiles dropped from 45 seconds to 4 seconds (for real-world/Mozart-KV250).

[thSoft]

This makes more real-world integration tests pass and editor performance enhance! Thanks!