Merge pull request #745 from edx/feanil/proper_extra_vars

Feanil/proper extra vars
adds new migration vars.
fixing extra notifies
syntax
fixing bad merge conflict
Updating alternatives.
Merge pull request #746 from edx/e0d/java-alternatives

Updating alternatives.
Merge pull request #743 from edx/e0d/es-bugfixes

bug fixes relate to re-location to /edx
Installing the bigdesk monitoring plugin.
updating to use stat module.
Merge pull request #747 from edx/e0d/es-bigdesk-plugin

Installing the bigdesk monitoring plugin.
Changes to update dhclient search domain.
Merge pull request #748 from edx/e0d/common-dhclient

Changes to update dhclient search domain.
wip
Simplifying template.
refactoring
adds a play to create the dbs in a vpc stack
Merge pull request #750 from edx/jarv/create-db-play

adds a play to create the dbs in a vpc stack
Add notifier to the reference template.
Merge pull request #751 from edx/feanil/notifier_cfn

Add notifier to the reference template.