Fix printing paths (gh#yast/yast-ruby-bindings#64)

Root of issue is that String in toString replace only special characters
lower then 32, but path use locale dependent isPrint call, so sometimes UTF8
characters can be replaced. This change make it consistent.
Disable tests that fails non-detereminic. Lets investigate it later by @mvidner
update testsuite to reflect UTF in paths
fix exporting comments for function calls

Example of badly exported comment is this modified code
from autoinstallation, where comments are attached twice
(second node is `auto in return):

{

  textdomain "autoinst";

  if (!true)
        return `auto;

  list progress_stages = [];
  y2milestone(
   _("Installing image into system...%1%2%3%4%5"),
   "",     // progress_title
   size( progress_stages ),  // progress bar length
   progress_stages,
   "",
   "");

  return `next;

}
ignore temporary files from testsuite
fix comments in list elements (gh#yast/yast-core#36)
Merge pull request #35 from mvidner/master

Fixed tests that would always succeed on oS-12.3, with "WARNING: could not find 'runtest'".
Merge pull request #33 from yast/more_comments_fixes

More comments fixes
Merge pull request #32 from yast/fix_path_printing

Fix printing paths (gh#yast/yast-ruby-bindings#64)
Merge pull request #31 from yast/disable_failing_test

Disable tests that fails non-detereminic. Lets investigate it later by @...
ignore products of testsuites and autodocs
DRY: factored out common Expect code
use C locale in tests
removed empty testsuites
version+changes