v5.0.3

Version 5.0.3:

• Updated ATNF Pulsar Catalog to v2.51
• Added an experimental version of fit_circular_orbit using sliders in examplescripts
• Added the ability to use pygaussfit.py without middle or right mouse buttons
• Fixed a couple memory issues in rednoise, thanks to @bwmeyers
• Explicitly set the random number seeds (for reproducibility) in makedata
• Several other very minor tweaks and bug fixes