Modified TClipboardHelper to have AddXXX methods for each format supported by program instead of a couple of generic overloaded methods. Updated using TCopyViewMgr accordingly.
This was done to get round a quirk in how TEncoding converts string to TBytes. MBCS encodings include termination 0 byte in bytes but Unicode encodings do not include any terminating 0 byte pair. TClipboardHelper now requires text data to be passed in required string format and ensures terminating zero bytes are written to clipboard.
