Divide :run.sh into parts. And delete it

* 00_core: the basic Bash routines
* git: the heart of TBS
* pkgbuild: provides s-makepkg
* pkgimport: import ArchLinux PKGBUILD into TBS
* zz_main: user interface
Remove lib/empty.sh (which is not useful now)
The header of the final output script
New way to build the final script

We do not use the geeky :sed; Now we use :cat to glue files