Support Encoding Configuration

In response to @Valem's merge request, I have added the ability to
support file encoding.
Merge remote-tracking branch 'upstream/master'

Conflicts:
	FlatFileReaders.Test/FixedLengthParserTester.cs
	FlatFileReaders.Test/SeparatedValueParserTester.cs
	FlatFileReaders/FixedLengthParser.cs
	FlatFileReaders/SeparatedValueParser.cs