Service template with substitution mapping definition can deployed

Service template with substitution mapping definition can deployed
standalone

According to specification of
http://docs.oasis-open.org/tosca/TOSCA-Simple-Profile-YAML/v1.0/TOSCA-Simple-Profile-YAML-v1.0.html,the
two main use cases:
1. No matter whether or not the service template has substitution
mapping definition，it can be deployed standalone;
2. Also can be imported and used as nested service template substituted
a node template with substitution mapping definition;
3. substitution mapping will expose node_type,may expose capabilities
and requirements.

JIRA:PARSER-78

Change-Id: I81ac940545f946925f6aa96a1b2ca0ccc9bbb076
Signed-off-by: shangxdy <shang.xiaodong@zte.com.cn>