Fixing #1038 by allowing nice URLs.

[ssbarnea]

Please take a look at my changes. They seem to fix #1038 or http://stackoverflow.com/questions/18191711/how-do-i-make-pelican-development-server-to-deliver-files-without-extension/18192139?noredirect=1#18192139

[coveralls]

Coverage remained the same when pulling 3b315fb on ssbarnea:master into 472abb6 on getpelican:master.

[almet]

thanks!