The layout process:
For computing the new layout for the children of any morph, we start with an initial rectangle which is provided as a reference.

Step 1: The first step of layout computation is to compute the minimum extent each of our children can have. The minimum extent is mapped through both the local layout frame of the morph (for relative positioning) and the global layout frame (for insets, such as cursor indication) to obtain the minimal size required for each cell.

Step 2: Based on the cell sizes, the number of cells we can put into each row and column is computed. For equal spacing, the maximum size of the cells is taken into account here.

Step 3: Based on the row/column sizes, we compute the extra space which should be added to each row/column. For
#leftFlush/#topFlush - we add all extra space add the end
#rightFlush/#bottomFlush - we add all extra space at the start
#centering - we add 1/2 of the extra space at start and end
#justified - we distribute the space evenly between the morphs
[NOTE: If any #spaceFill morphs are encountered during this step, #justified is implied and the space is exclusively and equally distributed between those #spaceFill morphs. This is for backward compatibility and should *never* be necessary in the new regime].

Step 4: The morphs are placed in the computed cells and the extra space is distributed as necessary. Placing the submorphs is done by mapping through the global and the local layout frame as requested.

Start point:
=> bounds: new rectangle for the morph.

Compute basic arrangement of morphs:
=> For each submorph compute minExtent
- if global layout frame inset in global layout frame
- if local layout frame inset in local layout frame
=> Compute number of morphs per, width and height of row/column
- if equal spacing based on max size
=> Compute extra space per row/column
- if centering = #justified; distribute space equally
- if centering #leftFlush/#topFlush (-1) add start extra
- if centering #rightFlush/#bottomFlush (1) add end extra
- if centering #centered add 1/2 extra to start/end
<extra space must be float and rounded accordingly!>
=> Place morphs in appropriate cells
- if global layout frame inset in global layout frame
- if local layout frame inset in local layout frame
<will likely cause #layoutChanged by submorphs>

Distribute morphs in row/column:

=> Compute the max length of each row/column

	optimized
	layoutLeftToRight:in: layoutTopToBottom:in: minExtentHorizontal: minExtentVertical:

	testing
	isTableLayout

	utilities
	indexForInserting:at:in: indexForInserting:inList:horizontal:target:

	layout	top
	computeCellArrangement:in:horizontal:target: Compute number of cells we can put in each row/column. The returned array contains a list of all the cells we can put into the row/column at each level. Note: The arrangement is so that the 'x' value of each cell advances along the list direction and the 'y' value along the wrap direction. The returned arrangement has an extra cell at the start describing the width and height of the row.
	computeCellSizes:in:horizontal: Step 1: Compute the minimum extent for all the children of aMorph
	computeExtraSpacing:in:horizontal:target: Compute the required extra spacing for laying out the cells
	computeGlobalCellArrangement:in:horizontal:wrap:spacing: Compute number of cells we can put in each row/column. The returned array contains a list of all the cells we can put into the row/column at each level. Note: The arrangement is so that the 'x' value of each cell advances along the list direction and the 'y' value along the wrap direction. The returned arrangement has an extra cell at the start describing the width and height of the row.
	flushLayoutCache Flush any cached information associated with the receiver
	layout:in: Compute the layout for the given morph based on the new bounds
	minExtentOf:in: Return the minimal size aMorph's children would require given the new bounds
	placeCells:in:horizontal:target: Place the morphs within the cells accordingly

	optimized	top
	layoutLeftToRight:in: An optimized left-to-right list layout
	layoutTopToBottom:in: An optimized top-to-bottom list layout
	minExtentHorizontal: Return the minimal size aMorph's children would require given the new bounds
	minExtentVertical: Return the minimal size aMorph's children would require given the new bounds

	testing	top
	isTableLayout

	utilities	top
	indexForInserting:at:in: Return the insertion index based on the layout strategy defined for some morph. Used for drop insertion.
	indexForInserting:inList:horizontal:target: