Omnibus Documentation Changes

• **Add an installation quick-start section**. (Fixes https://issues.cask.co/browse/CDAP-695)
Staged: http://stg-web101.sw.joyent.continuuity.net/cdap/2.6.0-SNAPSHOT-2.6.0_doc_updates/en/admin-manual/installation/quick-start.html
• **Add to installation index page**.
Staged: http://stg-web101.sw.joyent.continuuity.net/cdap/2.6.0-SNAPSHOT-2.6.0_doc_updates/en/admin-manual/index.html
• Re-arrange installation guide to flow better.
• Improve progress messages from build script.
• Add "Removing an Application" to the getting-started section.
• Added documentation for https://issues.cask.co/browse/CDAP-663, "Getting a Health Check".
• **Added docs on requiring path parameters to be percent-encoded** (https://issues.cask.co/browse/CDAP-728); see staging at:
- http://stg-web101.sw.joyent.continuuity.net/cdap/2.6.0-SNAPSHOT-2.6.0_doc_updates/en/reference-manual/http-restful-api/introduction.html#reserved-and-unsafe-characters, 
- http://stg-web101.sw.joyent.continuuity.net/cdap/2.6.0-SNAPSHOT-2.6.0_doc_updates/en/developers-manual/building-blocks/services.html#service-handlers, 
- http://stg-web101.sw.joyent.continuuity.net/cdap/2.6.0-SNAPSHOT-2.6.0_doc_updates/en/reference-manual/http-restful-api/service.html#requesting-service-methods

• **Modified property descriptions of the cdap-site.xml file** (https://issues.cask.co/browse/CDAP-454); staged at:
- http://stg-web101.sw.joyent.continuuity.net/cdap/2.6.0-SNAPSHOT-2.6.0_doc_updates/en/admin-manual/installation/cdap-site.html#appendix-cdap-site-xml
- http://stg-web101.sw.joyent.continuuity.net/cdap/2.6.0-SNAPSHOT-2.6.0_doc_updates/en/admin-manual/installation/installation.html#configuration

There may be additional cdap-site.xml properties that need flagging for the quick-start guide. If you know of any, please suggest in the comments.

• **Deprecated Procedures** in flavor of Services; https://issues.cask.co/browse/CDAP-413
Javadocs staged at: 
- http://stg-web101.sw.joyent.continuuity.net/cdap/2.6.0-SNAPSHOT-2.6.0_doc_updates/en/reference-manual/javadocs/deprecated-list.html
- http://stg-web101.sw.joyent.continuuity.net/cdap/2.6.0-SNAPSHOT-2.6.0_doc_updates/en/reference-manual/javadocs/co/cask/cdap/api/procedure/package-summary.html

And: https://github.com/caskdata/cdap/blob/develop/cdap-api/src/main/java/co/cask/cdap/api/service/http/HttpServiceRequest.java