Comment 14 for bug 1666924

I pulled out the change to dbConvert.c onto the 3.14 branch as I think this is a clear bug fix. http://bazaar.launchpad.net/~epics-core/epics-base/3.14/revision/12700

I didn't apply the change to dbAccess.c as this doesn't seem correct to me. I think dbr_precision_size will always be larger than sizeof(epicsInt32). As the DBRprecision union has 'long dp', the present code seems correct. The comment near DBRprecision in dbAccessDefs.h explains this.