new statistics

[ljwolf]

In addition to the Lee statistic in #51, we should also strive to add a few new statistics that have cropped up since PySAL was written:

• [x] LOSH, for local spatial heteroskedasticity.
• [x] ~SMAUP~, for scale-dependence
• [ ] CAGE statistic: Criterion for Aggregation Error
• [ ] Local Gamma statistic
• [x] Local Join Counts
• [x] multivariate join counts
• [x] local geary
• [x] multivariate (local) geary