Some more high-level documentation.
Merge topic 'more-docs'

1870f0b Some more high-level documentation.
Expand on key concepts.
Merge topic 'more-docs'

c8d84ab Expand on key concepts.
Fixed an adding null widget to layout error
Fixed a problem with updating table widget in qtGroupItem

For extensible group items, if the group items has a child group item,
creating new subgroups in this scenario is not showing the whole widget in
the table cell. I added a signal to the qtItem so that when a child group
item's widget size is changed, the parent table widget will force repaint.
Merge topic 'ui-annoyance-fixes'

b30ad99 Fixed a problem with updating table widget in qtGroupItem
8df3e6c Fixed an adding null widget to layout error
Use sphinx instead of Docutils' rst2html.

Sphinx uses docutils under the hood and adds the ability
to reference Doxygen documentation from within reStructuredText.
It generates multi-page HTML that is searchable instead of
a single page that can grow very large.
Also, it can target multiple output formats (besides HTML)
such as epub, pdf (via LaTeX), and more.
Merge topic 'sphinx-docs'

f926476 Use sphinx instead of Docutils' rst2html.
Use Sphinx documentation directives...

... in more of user-guide.
Merge topic 'sphinx-docs'

b6272c9 Use Sphinx documentation directives...
Add a Python tutorial.

This tutorial covers a good bit of the basic workflow
SMTK aims to support but is lacking a good model file
and an exporter.
Merge topic 'sphinx-docs'

965df4d Add a Python tutorial.