Disambiguate python use #1250 (#1251)

* Disambiguate python use #1250

Changed all calls to /usr/bin/python to /usr/bin/env python3.  Removed execute permissions on a lot of files that are not executable.

closes #1250

libexec/trick/convert_tv_file

@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/env python3
 
 import sys
 import xml.etree.ElementTree as ET

libexec/trick/create_top_dot_i

@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/env python3
 
 import os
 

trick_sims/SIM_rocket/scripts/Forces.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 import matplotlib.pyplot as plt
 import numpy as np
 

trick_sims/SIM_rocket/scripts/Mass.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
   
 import matplotlib.pyplot as plt
 import numpy as np

trick_sims/SIM_rocket/scripts/Position.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
   
 import matplotlib.pyplot as plt
 import numpy as np

trick_sims/SIM_rocket/scripts/Velocity.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
   
 import matplotlib.pyplot as plt
 import numpy as np

trick_source/trick_utils/SAIntegrator/examples/AsteroidFlyBy/plot_position.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import matplotlib.pyplot as plt
 import numpy as np

trick_source/trick_utils/SAIntegrator/examples/AsteroidFlyBy/plot_stepsize.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import matplotlib.pyplot as plt
 import numpy as np

trick_source/trick_utils/SAIntegrator/examples/BouncyCannonBall/plot_trajectory.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
   
 import matplotlib.pyplot as plt
 import numpy as np

trick_source/trick_utils/SAIntegrator/examples/CannonBall/plot_trajectory.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
   
 import matplotlib.pyplot as plt
 import numpy as np

trick_source/trick_utils/SAIntegrator/examples/DefiniteIntegral/plot_trajectory.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
   
 import matplotlib.pyplot as plt
 import numpy as np

trick_source/trick_utils/SAIntegrator/examples/DoubleIntegral/plot_trajectory.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
   
 import matplotlib.pyplot as plt
 import numpy as np

trick_source/trick_utils/SAIntegrator/examples/MassSpringDamper/plot_position.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import matplotlib.pyplot as plt
 import numpy as np

trick_source/trick_utils/SAIntegrator/examples/Orbit/plot_position.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import matplotlib.pyplot as plt
 import numpy as np