More work on version 4

[rdeago]

This PR pushes forward towards version 4.0, although a lot remains to be done.

All tests pass. Yay for me! 😄

Some significant changes have been incorporated in fix-warnings-by-the dozen mega-commits. My bad. I'll point to the relevant commits in the list that follows.

Changes include:

• Improvements to the build system (6289ec9, 468d053, e15ea45)
• Some hundred warnings fixed: from possible null dereferentiations to lack of parameter checking, from code style to XML documentation grammar... and it's not over yet! (30f7b8e, a1a089e)
• [ADD] New constructors for TestHttpClient (30f7b8e, a1a089e)
• [BRK] Property ITestWebServer.BaseUrl is now of type System.Uri instead of string (30f7b8e)
• [BRK] The MockFileProvider.GetRandomDataLength() method has become the RandomDataLength property (30f7b8e)
• MockFileProvider now uses a RNGCryptoServiceProvider to generate random data (30f7b8e)
• [ADD] TestWebServer can also be constructed from an Uri (previously it had to be a string) (30f7b8e)
• [ADD] Static property TestWebServer.DefaultBaseUri to complement the already-existing DefaultBaseUrl (30f7b8e)
• [BRK] Property RedirectModule.RedirectUrl is now called Location - the first in a series of name changes dictated by ~best practices~ StyleCop (30f7b8e)
• [ADD] All classes implementing IMimeTypeProvider now expose all methods of said interface as public. This means that two more public methods (GetMimeType and TryDetermineCompression) are available on FileModule, ModuleGroup, and WebServerBase<TOptions>. Hiding those methods could trigger some... interesting edge cases, as outlined in the documentation for the averted warning (30f7b8e)
• [BRK] Interface IWebModuleImpl (interesting to no one except module developers) no longer has a settable Container property; it has a SetContainer method instead, so the Container property of implementing classes can stay read-only (30f7b8e)
• [ADD] ValidatedNotNullAttribute can be applied to method parameters to signal static analysis that, once the method returns, the parameter is known to be non-null. More info here (30f7b8e)
• [BRK] The two WebSocketModule.SendAsync overloads, used to send string and binary payloads respectively, are now static methods (30f7b8e)
• [FIX] CorsModule, after converting allowed origins to all-uppercase (was all-lowercase in version 3), did case-insensitive comparisons with requests' Origin headers, resulting in CORS preflight false negatives. This bug is still present in version 3 (c37cf2e)
• [BRK][ADD] The newly-introduced ConfigurationLockSource has been renamed to ConfigurationLockTokenSource, while the renaming of ConfigurationLockToken to a simpler LockToken, and a LockTokenSource class, allow for use outside the scope of configurations ((784ec0e)
• [ADD] Static boolean properties WebServer.IsIPv4Supported and WebServer.IsIPv6Supported tell whether each of the two IP stacks is supported by the machine running EmbedIO (e1d86e3)

[lgtm-com[bot]]

This pull request fixes 3 alerts when merging 77d8dce1072708ff604562ed3289f75aac8660cd into 65d34efd8a71c2f35f7323e507c1e9a8f6816814 - view on LGTM.com

fixed alerts:

• 2 for Missing Dispose call on local IDisposable
• 1 for Poor error handling: empty catch block