add ntp type measurements for first time
remove verbose logging and add class explanations
include tests; needs more work and more coverage
Merge branch 'master' into addNTPtypes

Conflicts:
	ripe/atlas/sagan/__init__.py
Merge branch 'master' into addNTPtypes

Conflicts:
	ripe/atlas/sagan/__init__.py
better variable naming
move median calculation to parent class and reuse it in calculating median for ntp offset and rtts
add documentation for the upcoming ntp measurement types
add more test cases based on different results
final touches;removing unused imports;better variable names and remove dups keyword usage
python3 division leaves float
Added some helper methods to the Packet class and updated the tests and docs to reflect that.
Merge pull request #45 from RIPE-NCC/addNTPtypes

Added NTP support and cleaned up median math