CMake: GNUInstallDirs, export target zlib::zlib, CPack configuration, install PDB file

[rickertm]

Use GNUInstallDirs (${CMAKE_INSTALL_LIBDIR} instead of ${CMAKE_INSTALL_PREFIX}/lib) for improved platform compatibility
Export target zlib::zlib with corresponding config file
Add CPack configuration for packaging
Install PDB file with debug information for Debug and RelWithDebInfo builds

[tschw]

Very nice - modern buildfiles! Thanks a lot, @rickertm !

Are you sure about the CMake minimum version? I see target_include_directories first appeared in the documentation of version 2.8.11.

Not sure when @madler last looked at CMake, but guessing from version 2.4 that might have been a while ago. As a clue on what this is about, just in case:

# only needed once per dependent build tree:
find_package(zlib CONFIG)

# now to let my_project use zlib:
target_link_libraries(my_project PRIVATE zlib::zlib)

# that's all - no need to mess with directories, files, #defines, transitive dependencies

[rickertm]

Thanks for the feedback. You're right, it should be 2.8.11, I was only checking for GNUInstallDirs. Besides target_include_directories(), the module CMakePackageConfigHelpers also needs 2.8.8.

[madler]

See #1027 .