Slow performance when generating cells

[pleroux0]

When running a simple DCSFQ script the generation of the GDS file (nothing more) takes 2min. This is longer than the InductEx extraction which takes 40s.

[pleroux0]

The following takes 3s

import spira.all

The majority of this time is spent inside ABC internals (55%) and inspect:getmember (35%). Perhaps including more lazily would improve import performance since many features are optional.

EDIT: Misread callgraph.

[pleroux0]

When generating the DCSFQ 75% most of the time it's spent making deep copies (75%).