Get docs building with Sphinx 1.3.0

[jenshnielsen]

See #4213

[jenshnielsen]

It looks like the other issue relates to a new option of passing a string with -D to sphinx-build on the command line.

When building the small docs we set plot_format by adding -D plot_formats="[('png', 80)]" to the command line options this gets converted into [u"[('png'", u' 80)]'] (i.e. split on comma into a list of two items) which IMHO looks like a bug in Sphinx

According to the docs Sphinx now supports lists in this place separated by comma http://sphinx-doc.org/invocation.html so it makes some sense that is splits on comma but it should not happen inside a string.

[jenshnielsen]

Sphinx 1.3.1 was released fixing most of our issues. The remaining should be fixed by #4233

[jenshnielsen]

Done