Release 0.2.1 doc changes

Documentation changes for the 0.2.1 release.
Main change: release notes
Minor changes: 
- Fixed links, added an "all" target to the build.
- Added automatic versioning in the "Getting Started" guide, so that the code samples and links match the build version.
- Modified the FAQ, to improve formatting and content.
- Added the new "ClickStream" app as a reference in the examples section.
Staged at: http://stg-web101.sw.joyent.continuuity.net/tigon/0.2.1-r0.2.1_docs/en/release-notes.html