Adding support for a custom target dir while building, fixing a few issues...

Adding support for a custom target dir while building, fixing a few issues where the SITE.ipc folder/file was not created for a fresh build. Also adding check to the run script that tries to detect if we are doing a first build, and compensate for the first failure.

src/epics/util/lib/IPCx.pm

@@ -343,7 +343,7 @@ if ($::ipcxCnt > 0) {
 
     #Create the file if it doesn't exist
     if( !-e $iFile) {
-        open my $fc, ">", $iFile or "***ERROR: Could not create the empty IPCx parameter file $iFile\n";
+        open my $fc, ">", $iFile or die "***ERROR: Could not create the empty IPCx parameter file $iFile\n";
         close $fc;
     }