Let aws.cmd find python.exe on paths with spaces.

Before this commit, you'd get a vague "\Python\python.exe was unexpected at this time." message
when Python is installed in "C:\Program Files (x86)\Python". This fix always surrounds the
PythonExe variable's value with quotes so `if [%PythonExe%]==[""]` doesn't break.
Merge branch 'joeyespo-develop' into develop

* joeyespo-develop:
  Let aws.cmd find python.exe on paths with spaces.
Update changelog with #825