sw: don't dispose SwAccessibles in SwRowFrm::Cut()

This does not appear to work so well: for a row with multiple cells,
when the second cell frame's SwAccessible is disposed it will send an
event, and the AtkListener will then request all children of the row,
and this causes a new SwAccessible to be created for the first cell
frame that was disposed previously.

Unlike most other events, Dispose events cannot be sent delayed.

The SwAccessibles are disposed from ~SwCellFrm already, that should be
sufficient.

Change-Id: I6da72605e5386540f8d82535fca151e97d70869f
fdo#57197: sw: check that cells are still alive ...

... before firing events from them; use a thread-safe WeakReference.

(regression from 76c549eb01dcb7b5bf28a271ce00e386f3d388ba)

Conflicts:

	sw/source/core/access/acctable.cxx
	sw/source/core/access/acctable.hxx

Change-Id: Ie060d27cc44415e9a75b75027f5510577ac17a6e
sw: SwAccessibleDocument: fix crashes

Add missing SolarMutexGuards and also GetMap() may be 0 if it's
disposed. (regression from 76c549eb01dcb7b5bf28a271ce00e386f3d388ba)

Change-Id: I65312098e3d4cc6f686c3fc9e05dc8a6c4da34ce
Fix compilation error after conflict mis-resolution

Change-Id: I33510133dc984e9a7ddc6f2c42749d35c7cbe2b7