add tied parameters to nest_lc
Modify docs for numpy 1.8 compatibility.

Strings, not objects, should be used in the bandflux() and bandmag() methods
in models so that broadcasting works in numpy 1.8 (object arrays are
no longer broadcastable in this version, apparently).
a couple more tests
In fit_lc, handle m.covariance=None, m.errors=None
fix bug in previous commit
fix bug again
fix missing legend bug in plot_lc()
add tests
update salt2 data URL; add salt2 v2.4
bump astropy version requirement
update docs for release
change MANIFEST.in for proper release
ignore generated MANIFEST file
change rtd requirements to stable astropy
update docs and version for 0.5.dev
remove viewcode ext; astropy has it in v0.4.dev
Merge https://github.com/kbarbary/sncosmo