Added mnemonics for GPC motors, improved knife edge function

Load.py

@@ -237,6 +237,18 @@ mnemonics = {
     "GPC_EOS_DelayLine": {'source':'SCS_CDIDET_GRD/MOTOR/IMAGER',
                  'key':'actualPosition.value',
                  'dim':None},
+    "GPC_X": {'source':'SCS_GPC_MOV/MOTOR/X',
+                 'key':'actualPosition.value',
+                 'dim':None},
+    "GPC_Y": {'source':'SCS_GPC_MOV/MOTOR/Y',
+                 'key':'actualPosition.value',
+                 'dim':None},
+    "GPC_THETA": {'source':'SCS_GPC_MOV/MOTOR/THETA',
+                 'key':'actualPosition.value',
+                 'dim':None},
+    "GPC_THETAMAG": {'source':'SCS_GPC_MOV/MOTOR/THETAMAG',
+                 'key':'actualPosition.value',
+                 'dim':None},
     
     # FFT
     "scannerX": {'source':'SCS_CDIFFT_SAM/LMOTOR/SCANNERX',