Squashed 'clib/' content from commit e9e4714

git-subtree-dir: clib
git-subtree-split: e9e4714471c62e6058b9201930d3bece6fc71ef5
Merge commit '7ac2ae8822d67edfbda093b9fd1b060888738094' as 'clib'
Squashed 'zlib/' content from commit 5089329

git-subtree-dir: zlib
git-subtree-split: 50893291621658f355bc5b4d450a8d06a563053d
Merge commit '76a8592ccc1b06e2bc2dd8a153960a3f139c4202' as 'zlib'
Squashed 'cpplib/' content from commit 2657497

git-subtree-dir: cpplib
git-subtree-split: 2657497fefa885a3baf655b172d492debd923d7c
Merge commit '2252ebd17bf894cdcc5a5c7b067b59182630c914' as 'cpplib'
Adapt to locally imported clib and cpplib project subtrees

Now we can build it without dependent libraries (aside DirectX SDK).