Prior to this commit, WebJars users needed to use versioned links within
templates for WebJars resources, such as `/jquery/1.2.0/jquery.js`.
This can be rather cumbersome when updating libraries - all references
in templates need to be updated.
One could use version-less links in templates, but needed to add a
specific MVC Handler that uses webjars.org's webjar-locator library.
While this approach makes maintaing templates easier, this makes HTTP
caching strategies less optimal.
This commit adds a new WebJarsResourceResolver that search for resources
located in WebJar locations. This ResourceResolver is automatically
registered if the "org.webjars:webjars-locator" dependency is present.
Registering WebJars resource handling can be done like this:
```java
@Override
protected void addResourceHandlers(ResourceHandlerRegistry registry) {
registry.addResourceHandler("/webjars/**")
.addResourceLocations("classpath:META-INF/resources/webjars")
.resourceChain(true)
.addResolver(new WebJarsResourceResolver());
}
```
Issue: SPR-12323
polish
9e5a33c1b3