enable stable PD plugin in premake4.lua PyBullet

add a normalize in the setRotation axis/angle to be sure.
Add more code from the DeepMimic project, training doesn't work yet.

examples/pybullet/gym/pybullet_envs/deep_mimic/env/env.py

@@ -0,0 +1,13 @@
+from abc import ABC, abstractmethod
+import numpy as np
+from enum import Enum
+
+class Env(ABC):
+    class Terminate(Enum):
+        Null = 0
+        Fail = 1
+        Succ = 2
+        
+    def __init__(self, args, enable_draw):
+        self.enable_draw = enable_draw
+        return