First working version of the MasterMACS EPICS driver

Also added some test code

testpmacV3/db/motorMessage.db

@@ -0,0 +1,9 @@
+
+# The message text
+record(waveform, "$(P)$(M)-MsgTxt") {
+    field(DTYP, "asynOctetRead")
+    field(INP, "@asyn($(PORT),$(N),1) MOTOR_MESSAGE_TEXT")
+    field(FTVL, "CHAR")
+    field(NELM, "80")
+    field(SCAN, "I/O Intr")
+}