Cleaning up the Warp APIs

For the last one and a half years, I have been trying to implement HTTP/2 in Warp. Since both HTTP/2 implementations of Firefox and Chrome requires TLS for HTTP/2, I'm also trying to improve the performance of WarpTLS. In the process, I need to change the Connection data type. I felt nervous a bit because Connection is exported from the top module, Network.Wai.Handler.Warp. I believe there are only two users of this data type: Warp itself and WarpTLS. Normal users do not use it. So, Connection should be exported from the Internal module. This motivated me to clean up the Warp APIs.

The APIs of Warp 3.0 has the following issues:

• The top module exports many internal APIs which are prone to change.
• The Internal module does not export enough internal APIs.

Michael and I decided to clean up the Warp APIs. The following changes will be made in the version 3.1:

• Already deprecated APIs (settingsFoo) are removed from the top module.
• In the documentation of the top module, each API is categorized into either standard or internal.
• The Internal module exports all internal APIs including the internal APIs in the top module.
• Stopping exporting the Buffer and Timeout module which have been exported from the top module.

The standard APIs of the top module mainly consist of high-level run functions, Settings related stuff and necessary data types. We try to maintain these stably.

The internal APIs in the top module will be removed in Warp version 3.2. This is just documented. DEPRECATED pragmas are not added since there is no simple way to make an API deprecated in the top moudle but live in the internal module.

Warp version 3.1 is not released yet but is available from github repository. We will wait for a week or two to hear users' opinions.