Renames projects to match namespace names.

And adds proper namespace to the test project
Changes querystring args to be specified differently.

Rather than a (slightly hokey) convention in the URL pattern format,
querystring parameters are now specified explicitly as separate QueryArg
objects, with names.
Renames PotentialUrl to AppLocalUrl.

Which is a much better (more accurate) name.
Parses POST parameters, emits forms with correct method.

So requests with payloads (i.e., parameters in the body) are now correctly
parsed and dispatched.
Also, code for generting forms now takes RequestPatterns and emits the
correct 'method' attribute and URL.
Also, adds a unit test project. (Need to rename this stuff shortly.)
Renames directories & solution more sensibly.
Changes paths convention: does NOT start with '/'.

The rest of MVC uses route definitions which do not start with a slash, so
change our way of doing it to match.
Adds convenience methods to resolve UrlPatterns.

* UrlPatterns without parameters will implicitly convert to AppLocalUrl.
* UrlPatterns with parameters can be resolved using indexer notation.
  (Square brackets after UrlPattern expression to resolve.)
* Removes redundent extension methods now parameterless UrlPatterns
  implicitly convert to AppLocalUrl.
Replaces overloads with optional parameters.
Cleans up 'Urls' class: adds docs, removes 'Nullable' methods.

* Adds some doc-comments
* Adds Bool type class
* Removes Nullable method, since we already have the 'Or'/'OrNull'
  extensions methods which do the same thing less ambiguously and more
  tersely.
Changes how NullableComponent works. Does not allow null replacement strings.
Reworks 'example' project to be something bit more meaningful.

The 'Example' project is now a small, working (albeit completely trivial)
example. The examples before were really contrived, so hopefully this
makes it easier to see the actual advantages of using the library.
Some light tidying of extension methods.

Moves UrlHelper extensions to a separate class in System.Web.Mvc
namespace.

Adds a doc-comment to the otherwise-quite-obscure string.LinkTo(...)
extension method.
Upversions to 2.0.0