added resize feautre for table cells and columns

...io/gef/editor/editpolicy/BMotionStudioFlowEditPolicy.java

.../src/de/bmotionstudio/gef/editor/eventb/EventBHelper.java

...bmotionstudio/gef/editor/eventb/MachineContentObject.java

....editor/src/de/bmotionstudio/gef/editor/model/BTable.java

...tor/src/de/bmotionstudio/gef/editor/model/BTableCell.java

...tudio/gef/editor/observer/wizard/WizardTableObserver.java

.../src/de/bmotionstudio/gef/editor/part/BTableCellPart.java

...rc/de/bmotionstudio/gef/editor/part/BTableColumnPart.java