PAS now scans files with default extension set regardless of MIME type, non-default --scan-all | --all option added

[milosdjakonovic]

to scan all readable files.

MIME checking is removed from two methods in Scanner.

Diff shows a lot of changes, but most of it is indentation fix.

At least in theory there should be performance benefit from removing MIME checking (reduced fs io roundtrips).

This changes should address #24

If you accept this changes, IMO doc update and version bump is needed.