Support of multi byte characters in body

See https://github.com/connamara/quickfixn/issues/96
Revert "Support of multi byte characters in body"

This reverts commit 2815c41e98910d6f4b967c0c78d82488a8ea381e.
Fixed previous commit of FieldBase.cs
Merge branch 'master' of github.com:andbjorn/quickfixn into 97

Conflicts:
	QuickFIXn/Parser.cs
unit test for non-ascii in a stringfield
parser unit test
correct fixtest to be able to send utf-8; add a utf-8 test
changelog and credit
Merge branch '97' of github.com:gbirchmeier/quickfixn into 1.4.0beta

Conflicts:
	NEXT_VERSION.md