Merge pull request #1 from jounce/master

CDC growth charts added
update README, bump version
fix whitespace
correct errors in example usage
bump version
Adding head circumference from the WHO

Use "hcfa".

Note: Head circumference only applies to infants and toddlers, and is represented here up to age 5.

Conflicts:

	pygrowup/pygrowup.py
Fixing a bug
bump version, add AUTHORS file
add bootstrap script for setuptools
initial extraction of tests
add more tables, refactor table lookup
add who bmifa tables
add import to __init__.py

update README with new usage, test information
move test data into own directory
add note to README about table formatting
rename Growth to Calculator, add convenience functions
add proper logging, better param checks
remove print statements in helpers.py
use logger for Observation warnings, more comments
add version_info to __init__.py like django does
add another TODO item