Before the end of the text was selected when clicking below the end of
the text, rather than using the x position to find the appropriate
character on the last row that is closest to the pixel position.

RenderFile should add a source filter and call Render on each output
pin, while Render() should try to connect, first directly to any
existing renderers, and then using intermediates. It uses recursion
since this is the only possible way to implement Render sanely.

Does some security checks that it won't connect a filter to itself,
and also cleans up after a failed connection attempt.

These internal flags conflict with the Win32 API flags TPM_RECURSE,
TPM_RIGHTBUTTON, and TPM_CENTERALIGN respectively, which are all stored
in the same flag UINT.

As far as I can tell we support post ps blending in combination with
MRTs fine. Tabula Rasa needs this cap in order to enable some of the
higher graphics settings.

When the caret is at the start of a run, it uses the font of the
previous run for inserting characters.  The caret size previously was
the wrong height for the characters being inserted when the caret was at
the start of a line, but not the start of a paragraph so this patch
fixes this bug.

The check to see if the dwOutputBuffer is full was performed incorrectly
in RTFPutUnicodeString, however, this mistake was actually harmless
since it would just cause an extra loop that does nothing, then the
check would work properly with the variable fit equal to 0.

Checks were added for hexadecimal values that did not have valid
characters, and for EOF received before the final closing brace of the
rich text stream.  The error values were tested on richedit versions 1,
2, 3 & 4.1, and they were all the same for these cases.

The function ME_GetInsertStyle already checks for the case where there
is a selection, so there is no need to duplicate this code for
ME_GetSelectionInsertStyle.

Consecutively typed characters are grouped together to be undone
together.  The grouping of typed characters can be stopped by certain
events that are mentioned in MSDN's remarks on the EM_STOPGROUPTYPING
message, which is also implemented by this patch.