Dates: Fixed parsing issue with exact dates when using lte.

Date parsing uses a flag to indicate whether the rounding should be
inclusive or exclusive.  This change fixes the parsing to not use this
logic in the case of exact dates that do not have rounding syntax.

closes #8490
ok, but I get three test failures when I run the full suite:

```
Tests with failures:
  - org.elasticsearch.search.simple.SimpleSearchTests.simpleDateRangeWithUpperInclusiveEnabledTests
  - org.elasticsearch.index.mapper.date.SimpleDateMappingTests.testDayWithoutYearFormat
  - org.elasticsearch.index.mapper.date.SimpleDateMappingTests.testHourFormat
```

also, should we have the example from the original issue as test?