Merge pull request #931 from edx/jarv/release-ami-update

updating ami for official release
adding spaces to vars; addressing leaving loop expressions bare error
typos
reverting build-ami config.xml
reverting build-ami config.xml
reverting jenkins_admin defaults
reverting jenkins_admin defaults
typo error
Merge pull request #940 from edx/han/jenkins_admin

Han/jenkins admin
Fix forum LISTEN_{HOST,PORT} env variable names
Updating var syntax.
Adding non-empty check.
Merge pull request #941 from IONISx/fix-forum-env-variables

Fix forum LISTEN_{HOST,PORT} env variable names
The jenkins_worker roles needs to include the role defaults.

These roles now set various default passwords that the edxlocal role
needs.
adding ENABLE_AUTO_AUTH
explicitly state aws_region var
Merge pull request #944 from edx/jarv/performance-test-sandbox

adding ENABLE_AUTO_AUTH
Merge pull request #945 from edx/han/sendlogstos3

explicitly state aws_region var
adding user provided extra vars
Merge pull request #946 from edx/jarv/performance-test-sandbox

adding user provided extra vars