Add `jetzig test` command which runs build step `jetzig:test`.
Add `jetzig.testing` namespace which provides test helpers and a test
app.
Add tests to view generator (i.e. include tests for generated routes).
Use Karl Seguin's http.zig as HTTP server backend:
https://github.com/karlseguin/http.zig
Update loggers to use new `jetzig.loggers.LogQueue` to offload logging
to a background thread.
Numerous other optimizations to remove unneeded allocs.
Performance jump on a simple request from approx. 2k requests/second to
approx. 40k requests/second (Intel(R) Core(TM) i7-6700K CPU @ 4.00GHz).
Color support for Windows
Zmpl partial arg type coercion
Implement `jetzig.http.Request.params()` which parses either a JSON
request body or a query param string into a `jetzig.data.Value`.
Allow configuring params for static site generation - configure an array
of params for each endpoint which is then parsed at build time and a
separate JSON and HTML output is generated for each by invoking the
relevant view function and passing in resource ID/params. Params are
stored in generated `routes.zig` for route matching at run time.
