Fixed cluster rollback on scaling with heat engine

We can't allow stack to move into Error state if we want to use it futher.
disable_rollback parameter controlls such behavior. It is Ok to have errored
stack for cluster create and rollback since we will not be using it anyway. But
for scaling we need to keep it Active since we can just rollback in case of
error.

Change-Id: Iab1a58f4924ca6a7689060f71217956a72316517
Closes-Bug: #1337006
Added ability to specify security group for node group

Extended API to support list of security groups in node groups and
node group templates. Changed db schema and provisioning engines (both direct
and heat) accordingly.

Partially implements: blueprint cluster-secgroups

Change-Id: I49d3551f6987552ff6398e8c87e22388f914f287
Fixed DecommissionError bug

DecommissionError now can be raised without arguments
(with default message).

Change-Id: I4f8817b3cd6e58384438cb1a6444efbff0f1047b
Closes-bug: #1355084
Fix scale up cluster on CDH plugin with vanilla image

Change-Id: I5cda2b38be6532b13ccc7f31b6ea8ecf38c2247c
Closes-bug: #1354022
Remove unused parameter from CDH IT

* remove SSH_USERNAME parameter

Change-Id: I0af93f470bb43747f238d2e1ed01f29d4e5dfeb0
Merge "Added ability to specify security group for node group"
Merge "Fixed cluster rollback on scaling with heat engine"
Imported Translations from Transifex

Change-Id: I112663518d8f23755d34f7d7ef435abe8efba531
Merge "Fixed DecommissionError bug"
Merge "Imported Translations from Transifex"
Add translation support to plugin modules

Changed modules:
* sahara/plugins/base.py
* sahara/plugins/general/exceptions.py
* sahara/plugins/general/utils.py
* sahara/plugins/hdp/ambariplugin.py
* sahara/plugins/hdp/clusterspec.py
* sahara/plugins/hdp/configprovider.py
* sahara/plugins/hdp/hadoopserver.py
* sahara/plugins/hdp/versions/version_1_3_2/services.py
* sahara/plugins/hdp/versions/version_1_3_2/versionhandler.py
* sahara/plugins/hdp/versions/version_2_0_6/services.py
* sahara/plugins/hdp/versions/version_2_0_6/versionhandler.py
* sahara/plugins/provisioning.py
* sahara/plugins/spark/config_helper.py
* sahara/plugins/spark/plugin.py
* sahara/plugins/spark/scaling.py
* sahara/plugins/vanilla/hadoop2/config.py
* sahara/plugins/vanilla/hadoop2/config_helper.py
* sahara/plugins/vanilla/hadoop2/run_scripts.py
* sahara/plugins/vanilla/hadoop2/scaling.py
* sahara/plugins/vanilla/hadoop2/validation.py
* sahara/plugins/vanilla/plugin.py
* sahara/plugins/vanilla/v1_2_1/config_helper.py
* sahara/plugins/vanilla/v1_2_1/scaling.py
* sahara/plugins/vanilla/v1_2_1/versionhandler.py

Change-Id: Ia3dacd7ce5a77e8b51747d9c8e1a17fab266395e
Fixed Exception failures caused by i18n

Change-Id: If13bf9e91cbb8c7ba6cdb4df10c542af001054d2
Closes-bug: #1355065
Create etc/edp-examples directory

Merge content from sahara-extra/edp-examples and integration/tests/resources
into one directory under etc/edp-examples. This is part of the effort to
ultimately move edp-examples out of the sahara-extra repo and eliminate duplication.

The integration tests have been changed to reference the new
etc/edp-examples directory, and an EDPJobInfo class has been added to
eliminate path and config value duplication between the tests.

Partial-implements: blueprint edp-move-examples
Change-Id: I71b3cd21dcb9983fd6284a90316b12368481c700
Updated from global requirements

Change-Id: I67edfc5009aac754e736d4a68622cebfb95ca8d7
Merge "Add translation support to plugin modules"
Imported Translations from Transifex

Change-Id: Iefa529ec63599ec15fea4393811556e276ccc3e8
Unit tests for CDH plugin

partially implement: blueprint cdh-plugin

Change-Id: Ib3373d140d6c89e05c46d09df64bf692fa0d94ff
Merge "Updated from global requirements"
Merge "Imported Translations from Transifex"
Merge "Fix scale up cluster on CDH plugin with vanilla image"