Debug facilities:
- add a framework to easily add new ones
- add gdb as a first debug facility
- add patches for gdb
After the kernel checked its installed headers, clean up the mess of .checked.* files.
Reorder scripts/crosstool.sh:
- dump the configuration early
- renice early
- get info about build system early, when setting up the environment
- when in cross or native, the host tools are those of the build system, and only in this case
- elapsed time calculations moved to scripts/functions
Remove handling of the color: it's gone once and for all.
Update tools/addToolVersion.sh:
- handle debug facilities
- commonalise some code
- remove dead tools (cygwin, tcc)
Point to my address for bug reports.

 # Kernel options

 menu "Kernel"

 choice

     bool

     prompt "Target OS"

     default KERNEL_LINUX

 config KERNEL_LINUX

     bool

     prompt "linux"

     help

       Build a toolchain targeting systems running Linux as a kernel.

 endchoice

 config KERNEL_VERSION

     string

 if KERNEL_LINUX

 source config/kernel_linux.in

 endif

 endmenu