Web Services: GetValues returns all values when only startDate is specified

jirikadlec2[CodePlex]
In Web Services - REST Service Test when I set the startDate and I don't set the EndDate, I get all of the data values for the site and variable. I have the same problem when I set the endDate but don't set the startDate.

Correct behaviour should be:
If I set only startDate: Return all values after the startDate
If I set only endDate: Return all values before the endDate

This problem is in the GetValues and in the GetValuesObject methods.

Start with the REST service entry points for GetValues and GetValuesObject and trace how startDate and endDate are handled when either is omitted. Use the Web Services REST Service Test described in the issue to check each one-sided date case. Done means startDate returns only later values, endDate returns only earlier values, and both methods behave consistently.

Written by the indexing model from the issue text.