- CODABLOCKF: fix misencodation of extended ASCII 0xB0-0xB9 when

followed by digit (ignore 2nd byte of FNC4 when categorizing
  Code C characters)
- New `ZBarcode_Cap()` flag `ZINT_CAP_BINDABLE`, differentiated
  from `ZINT_CAP_STACKABLE`, and new Qt Backend method
  `isBindable()`
- CLI: fix `separator` check to use new `ZINT_CAP_BINDABLE` instead
  of `ZINT_CAP_STACKABLE`
- ZBarcode_Cap: add missing symbologies to `ZINT_CAP_BINDABLE` (was
  `ZINT_CAP_STACKABLE`)
- DOTCODE: pad rows if given number of columns instead of failing
  if rows below min (5)
- DBAR/composites: ensure stacked symbologies and composites are
  not stacked (set `symbol->rows` to 0)
- test suite: move `test_perf` routines into single test
  "test_perf";
  new "test_random" (based on "test_bwipp") to test various
  symbologies with random binary - discovered CODABLOCKF bug;
  expand "test_bwipp"
manual: Feeback: mention AZTEC -1 meaning min & MICROPDF417:
  doc new `ZINT_CAP_BINDABLE`
general: various code fiddlings and re-formattings

backend_qt/qzint.cpp

@@ -894,6 +894,10 @@ namespace Zint {
         return ZBarcode_Cap(symbology ? symbology : m_symbol, ZINT_CAP_COMPLIANT_HEIGHT);
     }
 
+    bool QZint::isBindable(int symbology) const {
+        return ZBarcode_Cap(symbology ? symbology : m_symbol, ZINT_CAP_BINDABLE);
+    }
+
     /* Whether takes GS1 AI-delimited data */
     bool QZint::takesGS1AIData(int symbology) const {
         if (symbology == 0) {