Create harvard-coventry-university.csl

Coventry University Harvard Reference Style - using version 3.0.1, September 2009.
In-line citation should be ok, however, there are still some reference missing in Biblography
Some code clean-up, added some macros and fixed errors
Fixed an error with link and template
Merge pull request #458 from jaegergaard/patch-1

Create harvard-coventry-university.csl