Implement BIP 9 GBT changes

- BIP9DeploymentInfo struct for static deployment info
- VersionBitsDeploymentInfo: Avoid C++11ism by commenting parameter names
- getblocktemplate: Make sure to set deployments in the version if it is LOCKED_IN
- In this commit, all rules are considered required for clients to support

src/main.h

@@ -551,6 +551,8 @@ extern CBlockTreeDB *pblocktree;
  */
 int GetSpendHeight(const CCoinsViewCache& inputs);
 
+extern VersionBitsCache versionbitscache;
+
 /**
  * Determine what nVersion a new block should use.
  */