Update Scons build environment to run on Python 3 (#9667)
* Update batch script and python wrapper for scons
* * Update copyright
* Remove obsolete _winreg import
* No longer pass unicode=True to gettext.install
* * sconstruct: xrange>range
* comInterfaces_sconscript: iteritems>items
* comInterfaces_sconscript: basestring>str
* nvdaHelper/archBuild_sconscript: xrange>range
* Liblouis sconscript: file>open
* cldrDict_sconscript: iteritems>items
* Disable developer documentation for now
* comInterfaces_sconscript: make sure that the byte compiled targets are picked up correctly by scons
* Fix espeak initialization and paths
* sconstruct: file>open
* Convert doxygen script to Python 3 and fix doxygen site tool
* Fix pot files creation
* Fix several issues to the dist builder
* Issue errors about str(bytes_instance), str(bytearray_instance)
* Update readme
