Support static conditionals

[guybedford]

Support for multiple conditional variations to be built into a static bundle based on inlining the conditional mechanism into the SFX wrapper itself.

[fluffywaffles]

@guybedford any status update on this?

Just ran into this trying to run a node build of my TypeScript project.

Would be willing to try to help if you want to point me in the right direction.

[guybedford]

@skorlir if using jspm 0.17 make sure you use the --node flag to get an exact build. This feature shouldn't be necessary for that use case.