Bring vibe.d's enforce closer to std.exception.enforce
Merge pull request #839 from Geod24/enforce-returns

Bring vibe.d's enforce closer to std.exception.enforce
Turned vibe.web.rest into a package
Adding example for future rest UDA fromHeader
Generalize findFirstUDA to findNextUDA
Adding funcattr and typetuple to vibe.internal.meta.all
Adding vibe.internal.meta.UDATuple to work with multiple usage of the same UDA
Add fromHeader attribute for REST interface, and handles it server side
Handle fromHeader client-side