Added docs on creating a private registry

Edited README.md to include instructions on creating a private registry, a new registry endpoint and then setting jspm to use that registry endpoint by default.
Documenting the advised private registry workflow

Updated README.md to reflect the advised workflow for switching to a private registry.
Merge pull request #245 from markstickley/master

Added docs on creating a private registry
add endpoint export
format-specific mains for cycles
semver fix
allow jspm init to work outside of package.json folder itself (#244)
Potential fix for local vs global install detection
Merge pull request #259 from crisptrutski/fix-local-mode-detection

Potential fix for local vs global install detection
windows paths adjustments
add jspm normalize API
dedupe overridden jspm properties
0.8.5
readme updates
help text fix
Merge stable fixes and features to beta