Add module to filter coincidences

Functions in this class build and perform queries to easily filter
coincidences based on station participation and station organization.
Add functions to API to only get 'numbers'
Use new API function to just get station numbers

Add closing of data to the example.
This is not yet handled by the class.
Update code for PyTables 3
Fix indentation
Add function to perform a custom query

This is also used by the other functions to perform their queries
Fix missing argument
Tests for first half of coincidence_queries
PEP8 fixes for some tests

Makes it a bit better, but not 100% compliant, just like unittest..
Add more tests for coincidence_queries

Clean up imports
Merge branch 'coincidence_queries'

Add module to easily filter coincidences process by CoincidencesESD.
Includes tests for most new functions, but not all.