added some of the Hogg 2010 implementations to fit_a_line
added some of the Hogg 2010 implementations to fit_a_line


git-svn-id: 4511b3d811903a91403bf66535cdd426db6c410e@567 7a03b35a-38c0-11de-8fef-1f5ae417a2df

keflavich/agpy,keflavich/agpy,astocko/agpy,astocko/agpy,keflavich/agpy,astocko/agpy,keflavich/agpy,astocko/agpy