React code (in jsx files) was not being extracted at all. Fixed this
by updating to edx-i18n-tools 0.4.5.

Also, template literals (feature of es2015) don't work well with
gettext at all. So convert those instances to HtmlUtils or
StringUtils interpolation calls.

FEDX-505

This reverts commit a7fa0c21.

Django can use pyinotify for watching files in runserver which should
save a lot of CPU work in docker.

LEARNER-1168

   during course import/export. Uses external code_block_timer module.
   Also, add script which validates XML file against an XSD file.
   Uses the unittest framework - but is currently skipped.