A crash of a draw-command voxeloctboolds on MMGT_OPT=0, MMGT_REENTRANT=1

Dear Julia,
Review please my fix.
In brief, I modified the method Voxel_OctBoolDS::OptimizeMemory(). The method "unsplits" (unifies) small voxels into one bigger voxel in case of all small voxels have the same value.
There was a simple mistake. I deleted the small voxels inside an iteration within a data map. The fix concerns removal of the voxels outside of the iteration process.
Any questions are welcome!

I forgot to say that the fix is located in SVN: http://svn/svn/occt/branches/23032

Small correction: parentheses to precise the precedence of operations

Thank you!

Dear Commenter 1,

SVN branch http://svn/svn/occt/branches/23032 has been moved to GIT CR23032 one.

Workbench KAS:dev:aan-23032-occt was created from git branch CR23032
(and aan-23032-products from svn trunk) and compiled on Linux platform.

There are following improvements in aan-23032-products regarding to
KAS:dev:products-20120321-opt

chl 936 G9

See results in
/QADisk/occttests/results/KAS/dev/aan-23032-products_23032012/lin
See reference results in
/QADisk/occttests/results/KAS/dev/products-2012021-opt_22032012/lin
See test cases in /QADisk/occttests/tests/ED
N.B. In order to launch testing case you can make use the following
instructions
http://doc/doku.php?id=occt:certification

Integrated into master