make core server only listen on 127.0.0.1
security fix: local connections only for internal servers
update about box atribution to match http://beakernotebook.com/about.html
fix capitalization of BeakerNotebook.com in about bubble
Update README.md
convert beaker.command to python in prep to expand it.  add reminder to improve plugin about command line processing.
on Mac, find and use JRE if that is all they have (vs JDK)
better detect mac
restrict nginx dynlib change to mac, where it is used
Merge pull request #217 from twosigma/spot/jdk-to-jre

fix for Issue #179 on mac
Merge branch 'master' into release-refact