New feature allowing working with Wikinews media dumps

[ckot]

I added a project named param with default value 'wiki' to the Wikipedia constructor, which allows one to specify a wikimedia project other than 'wikipedia'. This PR only adds support for 'wikinews'.

Description

• added a PROJECTS dictionary to allow lookup of values, allowing project aliases as well, and added exception handling for bad values
• actually a simple change. file_stub format is now '{lang}{project}/{version}/{lang}{project}-{version}-pages-articles.xml.bz2'

Motivation and Context

I wanted to work with Wikinews data dumps. Other packages exist for extracting the page text but this project already performs category extraction, which is what I needed, so simply adding a simple feature to this project rather than a more complicated one to another project seemed to be my best option.

How Has This Been Tested?

• As the feature is quite simple, I merely manually verified that the URLs generated by the modified file_stub value were still sane, and that my exception handling for unhandled values for the new project named param worked.
• I did think about defining _verify_url(url) and calling it in download() just prior to the actual downloading of the URL, which would simply do a HEAD request, catch a 404 and then backoff to see if BASE_URL/{lang}{project} existed to determine what error message to provide in the case that whatever mediawiki project doesn't exist for a particular language, but figured I should talk with someone about this first. This would provide a function which could be added to a unit test though.

Screenshots (if appropriate):

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [ x] My code follows the code style of this project.
• [ x] My change requires a change to the documentation, and I have updated it accordingly.

[ckot]

I only added support for Wikinews as I wasn't sure if my modifications to file_stub were robust enough to handle other Wikimedia projects. I suppose if it isn't, a _gen_file_stub(), which does project-specific branching to compute file_stub could be added

[bdewilde]

Thanks for the updates — this looks good to me!

[ckot]

Great! Thanks!