windows-specific install options

[gmabey]

• Provides new top-level option LWS_APPEND_DEBUG_SUFFIX_D to allow user to indicate that Debug compile version should have a name with a d suffix, thereby enabling the release-mode version to live alongside it.
• Adds logic to include the .pdb file in the install for Debug and RelWithDebInfo modes -- for the shared library only (of course).

[lws-team]

Sorry why is this needed? When I was using windows in the 1990s, the MSVC approach was two distinct build directories, ./Release and ./Debug which contained the corresponding outputs, without any chance of conflict.

CMake is very much on board with this, since the official way to build lws is to build to a subdir, eg, mkdir Release ; cd Release ; cmake .. -DCMAKE_BUILD_TYPE=release ; make ; cd .. ; mkdir Debug ; cd Debug ; cmake .. -DCMAKE_BUILD_TYPE=debug ; make

[gmabey]

Yeah I should have clarified. This doesn't relate so much to the build process as the installed layout: so that they can live alongside each other within a common installed directory. Since on windows you can only link "debug" executables with "debug" libraries, if you are switching back and forth between building the application in Debug and Release modes, then it's extremely convenient to have both Debug and Release modes of the libraries already compiled and installed somewhere.
It's certainly possible to install the artifacts to two separate directories (each with their own bin/, lib/ directories). However, in my case, there are a number of dependent libraries that are all being installed into a common install/{bin,lib,include} tree for the application to reach into.
With the .dll's (and the .pdb's, I might add) in one directory, it makes it simpler to set the PATH to just that one directory in order to find those shared libraries.
Furthermore, one may assign the cmake variable CMAKE_DEBUG_POSTFIX in the application's CMakeLists.txt so that the proper version of the .lib, .dll, and .pdb all get used for linking/debugging.
These cmake-provided facilities have been very handy to me in managing the awkwardness of the Windows library system.