More consistent method names in FileHelpers:
FileHelpers no longer mixes the terms "folder" and "directory", I settled on using "directory" only because that's what the Java File class does

Signed-off-by: Matthias Stevens <matthias.stevens@gmail.com>
Minor improvements to Collector file storage location detection logic:
- use FileHelpers#createDirectory(File) instead of combination of File.exists() and File.mkdirs()
- removed some duplicate code
- improved inline docs
- improved & additional exception handling

Signed-off-by: Matthias Stevens <matthias.stevens@gmail.com>