Option to switch between new-style and old-style IEEE logic gate symbols: sizing issues

[tomcl]

Many people prefer the old-style gate symbols to their newer rectangular forms. Issie originally used old-style symbols, nor uses new ones.

This applies to all the two-input logic gates and invertors.

The official guidance on old/new symbols remains neutral. So switching the Draw block between the two would be helpful. It could be done with a graphical change and nothing else (with ports still on a rectangular invisible outline.

The main problem with this change is that it makes the optimum size for these gates, relative to other elements, a bit smaller. being able easily to scale the sizes of different symbols is therefore valuable.

The current system keeps all symbols multiples of a large grid pitch which is too limiting, and only motivated by grid alignment.

[tomcl]

Arbitrary component size is now fine. Writing "old-style" gate symbols is now an easy change. The port positions on the current symbols would be OK for old-style making the change cosmetic only.