added python script

-I've been using this python script to make quick changes to the bitmanip controller

src/ieu/bmu/bitfieldedit.py

@@ -0,0 +1,32 @@
+""" 
+    bitfieldedit.py
+    Script that appends 0 just before the "illegal instruction" field of the bitstring
+    Written by Kevin Kim <kekim@hmc.edu>
+"""
+def addZero(s):
+    try:
+        indexSemicolon = s.index(";")
+        newS = s[:indexSemicolon-1]+"0_"+s[indexSemicolon-1:]
+        return newS
+    except: return s
+
+def main():
+    filename = input("Enter full filename: ")
+    n1 = int(input("Line number to begin: "))
+    n2 = int(input("Line number to end: "))
+    f = open(filename, "r")
+    flines = f.readlines()
+
+    #create list of lines from line n1 to n2, inclusive
+    lines = flines[(n1-1):(n2-1)]
+
+    #string to be printed
+    out = ""
+
+    for i in range(len(lines)):
+        lines[i] = addZero(lines[i])
+        out += lines[i]
+    print(out)
+
+if __name__ == "__main__":
+    main()