[1/3] Patches to implement EM_FORMATRANGE

[James McKenzie]

With the assistance of Dylan Smith <dylan.ah.smith at gmail.com>  much
progress has been made on implementation of this function.

This patch implements changes to dlls/riched20/context.c needed to
implement handling of target HDC parameters.

Programs reported to have problems in Bug 6254 were used for testing as
well as several others.

James McKenzie