adding viewer to htrace-hbase.
adding contents to doc and fixing typos.
Merge pull request #33 from iwasakims/viewer

adding viewer to htrace-hbase.
Edit. Add pointer to htrace-hbase Span Receiver
refactored span.js and added the description about timeline annotations to readme.
Edit of the htrace-hbase README
Update README to doc fix for 'Shell traces do not show in org.htrace.viewer.HBaseSpanViewerServer #34'
indent process_id based on hierarchy and popup timeline annotaations on mouseover.
updated README based on viewer enhancement.
fixed position of annotation popup based on window scrolling, with some formatting nit.
fixed sort order of spans in view.
Merge pull request #35 from iwasakims/enhance-viewer

Showing span hierarchy and timeline annotations in viewer.  Adds timing (in milliseconds output per span) and a red dot shows up when there is an annotation to view.
Merge pull request #36 from iwasakims/enhance-viewer

Refactor spans.js and add description about timeline annotations to doc
Small edit of README