Single cell resize

[Krzysztof Studnik]

related to #7072
Should we allow to change dimensions of cell (in cell properties dialog), when multiple different cells are selected in one row? Example:

• table 2x2
• select first row
• from context menu select cell properties, set width to 10%

The width of cells is set to 10%, but table is looking like 50/50.

• similar thing with different height for each cell in row

  1st cell with w10% h22px	2nd cell with w10% h11px
  no cell properties	no cell properties

Cell resize could be done perhaps by colspan/rowspan.
Word allows to resize single cell width. Google docs allow only resizing of row/column like our table resize plugin.

[Jakub Ś]

Since cells are displayed in a grid-like pattern and cells in given row/column take height/width of tallest/widest cell - this is rather not possible to do.