rpcrt4: Clear the memory of embedded complex types in ComplexUnmarshall when fMustAlloc is TRUE to avoid passing uninitialised memory to the unmarshaller.

Found by Valgrind.

Programs looking for this flag to verify if FF is present. And on which axes.

winhelp: Remove the search button, hook the index button to the Finder, and add a new summary button to go back to main page.

Fixes some graphical glitches that may occur otherwise.

widl: Rename find_type_helper, find_type and find_type2 to find_type, find_type_error and find_type_error2 respectively.

The caret's x position is stored in ME_TextEditor.nUDArrowX so that when
the caret is moved up or down, it will stay along the same horizontal
position, or at the end of a line.  Unfortunately, the value stored in
nUDArrowX was being unconditionally discarded in ME_ArrowKey, preventing
it from serving its purpose.

When dragging the scrollbar thumb with the mouse, the mouse is able to
move away from the scrollbar and keep scrolling so long as it isn't too
far away from the scrollbar.  This makes it easier to quickly scroll
with the mouse.

All that this patch changes is the distance that the mouse can be moved
away from the scrollbar before it is consider outside of the scrollbar
and returns to its original position.  The distances are proportional to
the size of the scrollbar.

Previously the window size and position was obtained in such a way that
when the window is closed while minimized, it would be hidden when the
program is started again.  Closing a maximized window would save the
size of the maximized window and use it as the normal/restored size when
the program is started again.

Ref pointers don't need a pointer ID and reserving space would render
the code incompatible with other clients. Note that the pointer
marshalling/unmarshalling functions didn't actually read/write pointer
IDs to/from the reserved space in the buffer.

rpcrt4: Fix NdrComplexArrayUnmarshall and NdrComplexStructUnmarshall to reuse memory for embedded pointers.

Certain WM_LBUTTONDOWN & WM_LBUTTONUP events should change focus to the
ComboBox (a child of ComboBoxEx), but instead the focus was set to the
Edit control.