Document the need for curl.
Merge pull request #144 from zzamboni/fix/need_curl

Document the need for curl
Add known issue for packages::installed reporting failure
Fix git pull instructions
For git commands to work you must be in the repository
(cherry picked from commit 21bbdecb8e27245ffa8243022633b16ee6a736bd)
Merge changes to installation and getting-started back to 3.5
Fix version number in packages back to 3.5
Some editing of style and markdown
(cherry picked from commit c0f7c2aa9213c8d12c479622eff7758920530a71)
Created two separate installation pages for Enterprise and Comm. Simplified the welcome and getting started pages.
Corrected spacing issue on Installation page.