Fix HDTcat to work under Windows

[fkleedorfer]

• Adds close() methods to LongArrayDisk and dependent classes. Also makes them implement Closeable. Closing LongArrayDisk causes the underlying RandomAccessFile to be closed, which was never done, leading to exceptions being thrown when those files were to be removed.
• Removes the setLength() call in LongArrayDisk, which also causes an exception under Windows. Nowhere in the docs is it stated that this call is necessary, the file only grows upon writing to it. The effect (under Windows) is simply that the exception goes away.
• Adds missing close() calls for some streams in FourSectionDictionaryCat
• Replaces Files.delete(Paths.get(...)) calls with new File(...).delete() calls, which inexplicably gets rid of the exceptions thrown under Windows when temporary files are deleted.

Fixes #127

[D063520]

I overflew the code and I run the tests. For me we can accept this pull request.
@fkleedorfer Thank you very much for this contribution!
PS: I did not check it under windows but I assume it is working there now ....

[D063520]

@fkleedorfer can you also remove this now ....

hdt-java/hdt-java-cli/src/main/java/org/rdfhdt/hdt/tools/HDTCat.java

Line 134 in b9ecbd1

System.out.println("NOTE: this tool is not working under WINDOWS! This is a well-known BUG!");

[fkleedorfer]

done

[mielvds]

Looks good. Anything else before I merge?

[D063520]

For me it is fine!

[mielvds]

Thanks both! I asked some minor questions, mostly about changes made to the core code

[D063520]

Basically there is no change to the core code. The code changes affect only hdtCat and the tests are passing. But it's good that you give a look too!

[fkleedorfer]

I asked some minor questions, mostly about changes made to the core code

Not sure where I can see these questions, @mielvds

[fkleedorfer]

From my side, this PR is ready to merge.

[mielvds]

Thanks @fkleedorfer @D063520 !