fix calling qdf with just an orbit
start on routine for fitting an orbit to data, #165
doc tweak
allow keywords for integration to be specified, #165
return what fit claims to return, #165
fix using vxvv_err and add test to comments, #165
fix documentation, #157
starton flipping the orbit, #166
fit orbit in lb or radec, also introduce flipping in FullOrbit, #165, #166
change implementation of flip, #166
test implementation of flip, #166
properly remove old flip in FullOrbit, #166
add documentation for flip, closes #166
actually test the flipping of linear Orbits, #166
properly transfer physical scales and coordinate-transformation parameters to new Orbit object, #166
propagate physical scale and coordinate-transformation parameters when return an Orbit object from within an existing Orbit object, #158
test that physical scale and coordinate-transformation parameters are properly propagated when adding orbits, #158
scale and coordinate-transformation parameters for linearOrbits and test this, #158
change Orbit such that vxvv is *not* stored in Orbit itself, but only in the OrbitTop instance that Orbit contains (to avoid confusion); fix pickling to properly store and restore the physical scale and coordinate-transformation parameters, #158
allow bovy_plot to work on the current figure