#2156 WSL: configure script needlessly checks for headers, defines, and functions

[Keith Marshall]

While exploring a possible resolution for [#2155], in configure.ac, I observe a raft of checks for header files, typedefs, structures, compiler characteristics, and library functions. Why? Every one of the checks refers to a feature or entity which is to be provided by the WSL package itself! Even if they do pre-exist, at configure time, the existing version will never be used; the provided versions will always replace them. There is absolutely no reason to check for them; they serve no useful purpose whatsoever. This is just so much rubbish, and a waste of resources; we should get rid of it.

[Keith Marshall]

Related to this, the configure script also creates a config.h header file. Why? Nothing uses it; nothing needs to use it. We've no need to create it. Let's get rid of it too, along with the unnecessary config.h.in template from which it is derived.