docker: exclude 'entrypoint' from comparing 'command' param with containers

The JSON the Docker API returns includes the container's ENTRYPOINT value (if it has one) with the 'Command' value. So instead of checking if `container['Command'] == module.params['command']`, we just check that `container['Command'].endswith(module.params['command'])` so the entrypoint won't affect a container being properly classified as matching the module params or not.

Also I refactored a super-long `if` statement into some temporary variables - I did it to help me figure out what was going wrong, and then it makes the code more readable so I kept it.

library/cloud/docker

@@ -489,8 +489,7 @@ class DockerManager:
         return inspect
 
     def get_deployed_containers(self):
-        # determine which images/commands are running already
-        containers = self.client.containers(all=True)
+        """determine which images/commands are running already"""
         image = self.module.params.get('image')
         command = self.module.params.get('command')
         if command:
@@ -504,13 +503,18 @@ class DockerManager:
         # docker will give us back the full image name including a tag in the container list if one exists.
         image, tag = self.get_split_image_tag(image)
 
-        for i in containers:
+        for i in self.client.containers(all=True):
             running_image, running_tag = self.get_split_image_tag(i['Image'])
             running_command = i['Command'].strip()
 
-            if (name and name in i['Names']) or \
-                    (not name and running_image == image and (not tag or tag == running_tag) and
-                    (not command or running_command == command)):
+            name_matches = (name and name in i['Names'])
+            image_matches = (running_image == image)
+            tag_matches = (not tag or running_tag == tag)
+            # if a container has an entrypoint, `command` will actually equal
+            # '{} {}'.format(entrypoint, command)
+            command_matches = (not command or running_command.endswith(command))
+
+            if name_matches or (image_matches and tag_matches and command_matches):
                 details = self.client.inspect_container(i['Id'])
                 details = _docker_id_quirk(details)
                 deployed.append(details)