Android APK D2D: Extend and refine code matching to PurlDB

[pombredanne]

This is a follow up to #1371

We already use directory matching to account for the specific of Android.

• from Android APK D2D: Match converted JARs to PurlDB #1371 (comment) by @mjherzog we may want to investigate more matching capabilities:

From recent Android project experience, my understanding of JADX is that (1) it will produce a set of .class files and a set of .source files neither of which will be a fingerprint match to the original Java code and (2) the decompiled source will be more divergent from the original source than the binaries. So wouldn't fuzzy matching for the .class files be the most important first step?