Fixing issue with pidof calls and use of python rather than python3

evaluation/demonstration/demo2_multiple_contexts/pythonHandlerScript.sh

-python processRequest.py $1
\ No newline at end of file
+python3 processRequest.py $1

evaluation/demonstration/demo2_multiple_contexts/run_demo.sh

 
     echo "Starting Middlebox"
     ../middlebox 8423 127.0.0.1:8423 webMiddlebox &
-    mboxpid=$(pidof ../mcmbox)
+    mboxpid=$(pidof middlebox)
 
     sleep .3
 
     echo "Starting Server"
     ../server ./pythonHandlerScript.sh &
-    serverpid=$(pidof ../mcserver)
+    serverpid=$(pidof server)
 
     sleep .3