Complete OpenCMISS-Zinc download page

Add PyZinc downloads. Group downloads by Zinc/PyZinc and OS platform.
Incorporate installation instructions.
Add improved platform download template.
Separate developer downloads.
Remove now-unused zinc-specific template and partial.
Build Zinc gallery with generic template.

Make gallery template generic so different pages can use it with their images and links.
Modify Zinc image gallery to use generic gallery template.
Add Cmgui image and link to Zinc gallery.
Move software list from template to content.

Convert software index template to a generic one-fourth column view. Put software links and information in content page.
Add OpenCOR to software. Remove Zinc Plugin at this level.
Restructure and edit Zinc documentation pages

Add API Reference, Examples and Support pages. Rename tutorials folder.
Make SourceForge primary download site for Zinc

Update download template to allow primary download location plus an optional alternative with a small link.
Keep ABI ftp site as alternative download for Zinc and PyZinc.
Add Cmgui 3.0.0 download links

Added a new download template which lists all the versions in expandable blocks.
Cmgui 3.0 is noted as pre-release since we don't have a static perl library linked in.
Fixed a little of the about and support pages.
Minor improvement to Zinc download and documentation
Improve OpenCMISS main page

Remove opencmiss-index template and reuse gallery-index template.
Standardise gallery templates

Make 3-column and 4-column gallery templates use same data structure and rename.
Change top software index to use 4-column gallery template.
Fix items raised in review
Merge pull request #51 from rchristie/master

Add Zinc and Cmgui v3.0 downloads and site improvements