Switch to SCons

[micahswitzer]

It's time.

Closes #324

[Kfeavel]

When you add the run task back in like we have in the Makefile, can you add the following to the Qemu options?

-monitor telnet:127.0.0.1:1234,server,nowait

[Kfeavel]

Remaining tasks:

• [x] Install Limine to echFS ext2 image (create Limine SCons tool)
• [ ] Create Limine ISO This can wait until #319
• [x] Build & run unit tests (with native toolchain)
• [x] Get git commit short hash
• [x] Move i686 toolchain to SCons tool
• [x] Update Kernel SConscript to handle Arch directory
• [x] qemu run phony targets
• [x] Documentation generation (Doxygen)

[Kfeavel]

Is there a way to make targets that the user can invoke like in the Makefile? We need a way to run the kernel in Qemu, so if we can't find a way to do that with SCons, we'll likely need to keep the Makefile.

[micahswitzer]

Is there a way to make targets that the user can invoke like in the Makefile? We need a way to run the kernel in Qemu, so if we can't find a way to do that with SCons, we'll likely need to keep the Makefile.

Yeah that should be possible with a Command

[Kfeavel]

Before merging, the liballoc repo should have the scons branch merged in and this branch update the submodule reference to xyris (with the newly merged SConscript)