dev-cpp/vexcl: improve docs WIP

Signed-off-by: Alessandro Barbieri <lssndrbarbieri@gmail.com>

dev-cpp/vexcl/files/add-sphinx-ext-autodoc-to-conf-py.patch

@@ -0,0 +1,11 @@
+--- a/docs/conf.py
++++ b/docs/conf.py
+@@ -45,7 +45,7 @@
+ # Add any Sphinx extension module names here, as strings. They can be
+ # extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
+ # ones.
+-extensions = ['breathe', 'sphinx.ext.mathjax',
++extensions = ['breathe', 'sphinx.ext.mathjax', 'sphinx.ext.autodoc',
+         'matplotlib.sphinxext.plot_directive']
+ 
+ breathe_projects = {'VEXCL' : 'xml'}