Some pre/post related stuff

Reload the onesix version config after the commands (addresses https://www.pivotaltracker.com/story/show/60360652)
Add a few more variables and also substitute them in the command (fixes https://www.pivotaltracker.com/story/show/66994828)

logic/BaseInstance.cpp

@@ -169,6 +169,12 @@ bool BaseInstance::canLaunch() const
 	return !(flags() & VersionBrokenFlag);
 }
 
+bool BaseInstance::reload()
+{
+	// TODO reload the instance settings
+	return true;
+}
+
 QString BaseInstance::baseJar() const
 {
 	I_D(BaseInstance);