Update the sensitivity test on number of users

In the CaseFinder Java class, we run top 5000 users with different
Location entropy file generated with different number of users.
Merge conflicts: casefinder does sensitivity test on user number

Merge branch 'master' of github.com:thekingofkings/gowalla-exp

Conflicts:
	data/Pair-glob-measure.txt
	src/probRela/CaseFinder.java
	data/select_topk.py will generate both topk_freq.txt and
	distance_*.txt