To prevent cases where ME_WrapMarkedParagraphs has not been called causing a NULL
pointer when editor_ensure_visible tries to get the row from the cursor.

Missing from b337c5b1, spotted by Fan
WenJie.

nCharOfs is the key for paragraphs added to the marked tree
If it is updated, re-add the entry to update its position

This was missed in 14c44d0b.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=55016

cf. 6b0836e3.

To avoid returning non-aligned reserved regions.

And merge reported free areas.

../dlls/msi/dialog.c:4476:11: warning: attempt to call free on non-heap object 'hdr' [-Wfree-nonheap-object]
    free( &rec->hdr );
          ^

queue_task cannot free the struct because it doesn't know whether the
struct contains pointers to other dynamically allocated memory that also
needs to be freed (as is the case with struct send_request).