This changes:
1. Support 'Conditions' for AWSTemplateFormatVersion: 2010-09-09
2. Support 'conditions' for heat_template_version: 2016-10-14
3. There is no need to add a new HeatTemplateFormatVersion template,
because we decide to support conditions in AWSTemplateFormatVersion
and heat_template_version: 2016-10-14, so remove the
HeatTemplateFormatVersion.2016-10-14
4. Move the definition of function 'equals' to hot/functions.py
5. Mark 'equals' as condition function which supported in conditions.
Change-Id: I2e7bdfa1c2052e75f35f2bd0003cdc170188d8b8
Blueprint: support-conditions-function
70c4ab3fcf