This change introduces ParameterAttribute to specify a bindable
component parameter. As of the 0.3 release of Blazor we plan to make
[Parameter] required to make a property bindable by callers.
This also applies to parameters when their value is set by the
infrastructure, such as `Body` for layouts, and route paramters.
The rationale behind this change is that we think there is a need to
separate the definition of properties from their suitability for a
caller to set them through markup. We plan to introduce more features in
this area in the future such as marking parameters as required. This is
first step, and we think that this approach will scale nicely as we add
more functionaly.
The 0.3 release seems like the right time to change this behavior since
we're also introducing `ref` for captures in this release.
* Updates the router component to scan for components within assemblies.
* Parses the templates on `[Route]` in component instances and builds a
route table that maps paths to components.
* Uses the route table to map paths to components.
Ryan Nowak
Steve Sanderson
Javier Calvarro Nelson