Render reStructuredText in *.txt files. (BB-2043)

Most Python packages are using reStructuredText to format e.g. their README files. According to the //Hitchhiker’s Guide to Packaging [1]//, README and other documentation files should have the *.txt extension.

It would be nice if Bitbucket would not only render *.rst files as rst, but also *.txt files. The Python Package Index does this already.

If an error occured while parsing *.txt files, you could simply fall back to plain text. I don’t think this should be a problem since *.rst files could also contain errors (so you should already handle them anyways).

If you are afraid that there will be a lot of errors for non-Python projects, you might activate this featere only for projects labeled as Python projects.

[1] http://guide.python-distribute.org/creation.html