Update wiki pages to distinguish between Platform and the Reference application

Earlier the term OpenMRS was used in the wiki pages to represent the Platform and RefApp both. However, now, there are clear boundaries between the two and our wiki pages need to be updated.

The task is to find a wiki page that still uses OpenMRS for both the products and then update them accordingly.
p.s : Platform is OpenMRS core/ TRUNK (compare it to a kernel) while the Reference Application is a bunch of modules that interact with the Platform. (compare it to a desktop environment)
The task will be considered complete for every 3 pages you can find and edit