Moving chibi snow libraries under chibi namespace.

--HG--
rename : lib/snow/commands.scm => lib/chibi/snow/commands.scm
rename : lib/snow/commands.sld => lib/chibi/snow/commands.sld
rename : lib/snow/interface.scm => lib/chibi/snow/interface.scm
rename : lib/snow/interface.sld => lib/chibi/snow/interface.sld
rename : lib/snow/package.scm => lib/chibi/snow/package.scm
rename : lib/snow/package.sld => lib/chibi/snow/package.sld
rename : lib/snow/utils.scm => lib/chibi/snow/utils.scm
rename : lib/snow/utils.sld => lib/chibi/snow/utils.sld
rename : lib/snow/snow => tools/snow-chibi