Use relative imports for consistency; pep8
Fixed line wrap in findstars.py
pep8 arrayutils.py
Fixed prf_nan comparison to True
Merge pull request #70 from larrybradley/imports

Use relative imports for consistency; pep8
Merge pull request #71 from larrybradley/pep8

arrayutils: pep8 and fixed prf_nan comparison to True
Ensure that downsample.pyx preserves image flux
Added cython compiler directives and array index cleanup in downsample.pyx
Added upsample cython function
Import util functions into top-level utils namespace
Import cython code in try...except block
Merge pull request #72 from larrybradley/utils

Added upsample cython function; fixes to downsample function to preserve image flux
Add photutils.datasets sub-package
Add fermi_counts.fits.gz example image file
Add datasets sub-package to docs
Various improvements to datasets code and docs