See #2, #1385 for context. Superseeds #1566.
This is the docutils parsing, transforms and writing part, building on PR #1930. It contains a pseudo-package, `sphinx_pep_extensions`, which itself contains:
### Docutils parsing:
- `PEPParser` - collates transforms and interfaces with Sphinx core
- `PEPRole` - deals with :PEP:`blah` in RST source
### Docutils transforms:
- `PEPContents` (Creates table of contents without page title)
- `PEPFooter` (Dels with footnotes, link to source, last modified commit)
- `PEPHeaders` (Parses RFC2822 headers)
- `PEPTitle` - Creates document title from PEP headers
- `PEPZero` - Masks email addresses and creates links to PEP numbers from tables in `pep-0000.rst`
### Docutils HTML output:
- `PEPTranslator` - Overrides to the default HTML translator to enable better matching of the current PEP styles
Adam Turner