get rid of piForeach

apply some code analyzer recommendations
ICU flag now check if libicu exists
prepare for more accurate growth of containers (limited PoT, then constantly increase size)

libs/main/text/pistring.cpp

@@ -1515,6 +1515,7 @@ PIString PIString::takeNumber() {
 			}
 			phase = 9;
 			break;
+		default: break;
 		}
 		if (phase == 6) {
 			if (c == 'f' || c == 's' || c == 'u' || c == 'l' || c == 'L')