Support parsers creating multiple entries from the same file
Make it possible for parsers to generate multiple entries from the same file. The different entries should be separated by a suffix, i.e. metadata.mainfile = path/to/mainfile[suffix]
. I.e. the concept of a "mainfile" is thus extended so that it may not necessarily be a path to a file: it can also be a path to a file plus a parser-generated suffix.