Change a warning to an error.  Previously, we had only warned if a function
specified its return type but did not return a value along one of its control
flow paths.  This will cause unpredictable behavior when return temps do not
initialize themselves by default (relying on other assignments to initialize).
Now, the behavior will be deterministic and will correctly not allow the
program to execute.
Update the previously known test case affected.

The test functions/hilde/retTypeNoRet.chpl displayed the warning behavior
described in the previous commit.  Since the test now fails to compile, I have
altered the .good file accordingly, and modified the test to only include the
minimum calls which will generate the error message.
This test previously generated a warning because the function did not return
a value when the return type was specified.  However, the point of the test was
a valgrind error that still exists when no return type is specified.  I decided
to remove the specified return type.  This program will now complete with only
the valgrind error remaining.
These five tests were properly checking that we detect when a function fails to
return a value, so it was appropriate to alter them for an error rather than a
warning with output.
Futurizing these tests.

As the functions in question currently stand, a value will always be returned,
but the compiler is under the impression this is not the case and so is
generating an error.  With proper analysis, these two cases should pass, so the
issue is now a future for both of them.
Merge pull request #39 from lydia-duncan/changeWarningToError

Change warning to error