Use CMake build system

[TheAssassin]

The current Makefile does not check any dependencies and is overall a bit limited. How about setting up a modern build system like CMake?

[wllm-rbnt]

I gave it a shot on my fork.

To test it, first clone my branch and enter the repo:

$ git clone -b cmake https://github.com/wllm-rbnt/squashfs-tools/
$ cd squashfs-tools/squashfs-tools

Then, edit user defined variables & options in CMakeLists.txt (top section).

Then you can test it using Ninja:

$ sudo apt install ninja-build
$ cmake -B build -G Ninja
$ ninja -C build
$ ninja -C build install

or make

$ cmake -B build
$ cd build
$ make
$ make install

DATE, VERSION and YEAR have to be edited manually.
Only pre-built manpages installation will work for now.
Building with LZMA1 support is not supported.

William