New playbooks for the sandbox configuration

edx_sandbox for edx-east and an edx_sandbox reference
new launch_instance role for bringing instances up using the ec2 module
new edxlocal role for installing local dependencies
making the default nginx templates more generic
setting default nginx ports for the edxapp services

This allows you to access services without setting
up subdomains
adding handler for running syncdb and migrate

Run only when migrate_db is set which will be the case
for bringing up new instances
reference sandbox configuration

Configured to use localhost for mongo, mysql, memcache
README update
readme update
changing hosts to launched for configuration
changing hosts to launched for configuration
adding tags to syncdb and migrate
removing some more edx specific info from the sandbox template

also adding comments
Merge pull request #110 from edx/jarv/edx-sandbox

Jarv/edx sandbox