test must execute scripts as scripts to save output
fix nan test issue

throws expception when list contains non-float data, if that happens
just punt
use default ticker/formatter

Let axes supply default instances of tickers and formatters (can be
overridden)
glyphs tests working with recent changes

grids need to be configured with an axis
sign notebooks

for ipython 2.0 notebooks need to be signed in order to load html/js