Minor EC2 bug fixes turned up by GCE development. #4069

* GAHP command names should be case-insensitive.
* A CURL structure can be leaked in AmazonRequest::SendRequest() on an
  error.
* In EC2Job::EC2Job(), the variable 'value' needs to be cleared between
  ad lookups.
edit of HGQ rewrite, to correct spelling, and add back in omitted info.
The prose on surplus has not yet been edited.  #4061
Merge branch 'V8_0-branch' of /p/condor/repository/CONDOR_SRC into V8_0-branch
Merge branch 'V8_0-branch'