make structures_dict private
Added start of migration guide for users of previous versions of astrodendro
Added acknowledgment section and make developer list more uniform
Added migration guide link to main docs page
Minor fixes to migration guide
Remove flux and luminosity attributes for now, and finish renaming analysis properties
Added a sub-module that deals with flux conversions
Implemented Fnu per beam
Consolidated all_structures and prefix_structures
Merge pull request #32 from astrofrog/migration-guide

Add a section to the documentation on differences with previous versions of ``astrodendro``
Made tests independent of astropy.units version (which removes parentheses in Astropy 0.3 if denominator only has a single unit)
Re-implemented flux properties and only warn when necessary about using default meta-data values.
Tidied up analysis: warnings for meta-data are only raised when the values are needed and the defaults are used, exceptions for strict meta-data are only raised when needed, Metadata class(es) now implement type checking, and more of the analysis properties are returned as quantities.
Show units in printed table output
x_cen, y_cen, and v_cen are now explicitly in pixel coordinates if no WCS is specified
Make it so that rather than defaulting to u.pixel in the metadata, u.pixel is used if the spatial_scale is missing - this leads to less confusing errors - e.g. 'spatial_scale is needed' rather than 'spatial_scale should be an angle' (the latter will be confusing if the user hasn't set the spatial_scale at all). Also improve consistency of variable naming in flux calculation compared to the rest of the analysis code.
Fix bug in calculation of beams_per_pixel
Merge pull request #54 from astrofrog/analysis-improvements

Remove flux and luminosity attributes for now, and finish renaming analysis properties
Ensure that _idx is an integer in output table, and sort by _idx
Fixed broken script to to API change