$lte/$gte queries fail for Dates on MySQL

[kmalakoff]

2. Model.find (cache: false, query_cache: false) Handles $ne for dates:
   Uncaught AssertionError: all but START DATE found

3. Model.find (cache: false, query_cache: false) Handles $lt and $lte boundary conditions:
   Uncaught AssertionError: first model found

4. Model.find (cache: false, query_cache: false) Handles $lt and $lte boundary conditions with step:
   Uncaught AssertionError: two models found