FLUME-677: Update build instructions in devnotes

Review Request #1840 - Created June 23, 2011 and submitted - Latest diff uploaded

Jonathan Hsieh
aaron, ahmed, andrew, arvind, esammer
This is a document that should be good for all folks to read, and review.  

I believe this will eventually get pushed out to the apache flume wiki but I wanted to get all this content in while it is fresh.

The deleted sections, files, or options are features (some would say "grossness") that are no longer relevant due to the maven transition.
project builds, asciidoc compiled version of DEVNOTES looks good after a quick scan.