Python API documentation generation tool Code

- Added --no-submodule-list option

- Added the latex commands \EpydocUserSection, \EpydocUserSubsection,
and \EpydocUserSubsubsection, used to add section headings inside of
docstrings.
- Added TEMPLATE to latex stylesheets

- When pre-importing modules, catch any ImportError exceptions, and
ignore them for now -- we'll report them during documentation
generation.

- Added options --max-html-graph-size and --max-latex-graph-size

- Use different minimum graph sizes for latex & html output. These
sizes default to the values DotGraph.DEFAULT_LATEX_SIZE and
DotGraph.DEFAULT_HTML_SIZE, respectively. (This will make it easier
to add a command-line option to change those defaults.)

- DocstringLinker.url_for() is now an optional method

- Removed stale (unreachable) code

- DocstringLinker.url_for() is now an optional method

- DocstringLinker.url_for() is now an optional method

- Added max_width and max_height attributes to DotGraph -- if the graph
is larger than this, then it will be scaled down. Default value is
6 inches wide by 8 inches tall.