Updated Getting Started:
* Word wrap - easier to view on GitHub
* Corrected problem where Brooklyn versions were not being shown (site.brooklyn-version)
* Clarified SSH needs and instructions
* Changed BROOKLYN_HOME to BROOKLYN_DIR. Two 'homes' (User, Brooklyn) had caused confussion.
Added note that ~/.brooklyn != BROOKLYN_DIR
Merge pull request #956 from jdtoy/getting-started-ssh-clarification

Docs: Getting Started tweaks.