This changeset adds the `highlight_options` configuration value, which
specifies a dict of key-value pairs to pass to the Pygments highlighter
specified with `highlight_language`. For example, specifying
`highlight_options = {'funcnamehighlighting' : False}` for the 'php'
lexer will disable function name highlighting.
Both the HTML and LaTeX writers have been updated to include the
options when calling `highlight_block()`, as long as the currently
selected language matches what was set with `highlight_language`, i.e.
not when modified by `highlight::` or `code-block::` directives.

* rename a few test modules to make the names more consistent

* do not copy/use Sphinx from build/ (unnecessary without 2to3)

* use a temporary dir for *all* test projects, the source tree
  will stay pristine that way  (default is tests/build)

* speed up tests by ~3x by splitting up test projects and avoiding
  rebuilds