phpmd - refine handling parsing errors (visual warning in html, enable counting them for exit code)

[zdenekdrahos]

1. Find open phpmd issue for testing parsing errors, e.g.:

   <?php if (true): ?>
       <?php if (true): ?>
       <?php endif ?>
   <?php else: ?>
   <?php endif ?>

2. Show visual warning in html report phpqa --config tests/.ci/ --tools phpmd -v
   
3. Edit phpmd.ignoreParsingErrors: true|false, check exit code (closes Exit code is ignored from phpmd (parsing errors for new php syntax) #230)

   $ nano tests/.ci/.phpqa.yml # phpmd.ignoreParsingErrors: true
   $ phpqa --config tests/.ci/ --tools phpmd:0
   $ echo $?
   0
   $ nano tests/.ci/.phpqa.yml # phpmd.ignoreParsingErrors: false
   $ phpqa --config tests/.ci/ --tools phpmd:0
   $ echo $?
   1