Allow switch off edm schema validation to improve performance

Validation of all edm entities works always. This increases de-serialization time significantly (maybe even 10 times for particular non-string property of entity measured in nanos).

For end user of Olingo these properties can be validated before Olingo does deserialization.

Some configuration property is required to switch off default Olingo validation.

Example EdmString.internalValueOfString:

if (isUnicode != null && !isUnicode && !PATTERN_ASCII.matcher(value).matches()
        || maxLength != null && maxLength < value.length())

{       throw new EdmPrimitiveTypeException("The literal '" + value + "' does not match the facets' constraints.");     }

This code can be optional, switched on by default.