Limits
cna.limit.ne reads the North-East coordinate of project limits. Returns a table with values. Mutating this table will not change limits in CadnaA.cna.limit.sw reads the South-West coordinate of project limits. Returns a table with values. Mutating this table will not change limits in CadnaA.cna.limit.left, cna.limit.right, cna.limit.top, cna.limit.bottom reads the appropriate value of the current limitscna.limit.calc() recalculates the limitscna.limit.set(l, b, r, t) sets the limits manually, defined by two points at the bottom left (l, b) and upper right (r, t) corners