configuration brainstorm

etc/config/rust-overrides.defaults.properties

+overrides=&edition:&architecture:&optimization
+
+group.edition.name=Edition
+group.edition.flag=--edition <value>
+group.edition.source=helpParse(--edition)
+
+group.architecture.name=Target/Architecture
+group.architecture.flag=--target <value>
+group.architecture.source=lineParse(--print target-list)
+
+group.optimization.name=Optimization
+group.optimization.flag=-<value>
+group.optimization.source=manual
+group.optimization.options=opt
+
+override.opt.name=Yes
+override.opt.value=O