Follow up to r887178; replace ASCII control characters with glyphs from the Control Pictures Unicode range and refactor the escaping funcs.
Follow up to r887178; replace ASCII control characters with glyphs
from the Control Pictures Unicode range and refactor the escaping funcs.

* tools/dev/gen_junit_report.py
  (xml_encode_map): New escape mapping, extracted from xml_encode.
  (special_encode_map): New escape mapping.
  (replace_from_map): New function. Munge string with an escape mapping.
  (xml_encode): Reimplement with replace_from_map and xml_encode_map.
  (escape_special_characters): Reimplement with replace_from_map
   and special_encode_map.

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion