added new quantity function to return astropy quantity, all other functions now use this function to get the value or unit, trying to preserve api
update to use Quantity, getting warning from astropy still
Pass draw_limb kwargs to patch.Circle
Pass draw_grid kwargs to plot
fixed logical lightcurve example
made sure the measurement in SWAP is truly a string as required
Add full changelog
add changelog for 0.3.2
add more to 0.3.2 changelog
Add patch to #471 to changelog
bump version numbers
updated _si to use astropy constant objects

also fixed bug in wcs introduced by using new constants
Removed models from constants, created new module
fixed some errors, updated print_all(), updated doc strings
updated doc string, removed units
fixed failing test in wcs due to new constant object
Fixed #617
Merge pull request #644 from Cadair/master

Forward-port 0.3.2 updates into master
Fix a bug in the HMI source
tidy up norm() loose ends and make a property