#26 grid layout package for asymptote at figure level

[Sebastian Blatt]

As requested in the forum discussion here

https://sourceforge.net/p/asymptote/discussion/409349/thread/08d2b53e/

I am adding a patch for a grid layout package at the figure level. The corresponding asymptote code and an example can be found here

https://github.com/blatts/table-figure

Best,

Sebastian