Fix Py2Exe / Py2App

Fixes the C PoW loading in frozen apps (Windows and OSX)
Cleaner fallback in PoW if something goes wrong

src/proofofwork.py

@@ -10,6 +10,11 @@ import openclpow
 import os
 import ctypes
 
+if frozen == "macosx_app":
+    curdir = os.environ.get("RESOURCEPATH")
+elif frozen: # windows
+    curdir = sys._MEIPASS
+else:    
     curdir = os.path.dirname(__file__)
 bitmsglib = 'bitmsghash.so'
 if "win32" == sys.platform:
@@ -128,13 +133,18 @@ def run(target, initialHash):
         try:
             return _doGPUPoW(target, initialHash)
         except:
-            pass # fallback to normal PoW
-    if frozen == "macosx_app" or not frozen:
+            pass # fallback
     if bmpow:
         try:
             return _doCPoW(target, initialHash)
         except:
-                pass # fallback to normal PoW
+            pass # fallback
+    if frozen == "macosx_app" or not frozen:
+        # on my (Peter Surda) Windows 10, Windows Defender
+        # does not like this and fights with PyBitmessage
+        # over CPU, resulting in very slow PoW
+        try:
             return _doFastPoW(target, initialHash)
-    else:
+        except:
+            pass #fallback
     return _doSafePoW(target, initialHash)