luajit: refactor without dont-strip.patch

the variable TARGET_STRIP does the job
luajit: refactor without shared-lib.patch

the variable BUILDMODE does the job
luajit: handles BR2_PREFER_STATIC_LIB
luajit: add host-luajit
luarocks: allow to work with host-luajit

when we use luajit on target
ljlinenoise: new package
lpeg: new package
cosmo: new package
lua-iconv: new package
luajson: new package
lualogging: new package
dado: new package
lrandom: new package
lua-testmore: new package
lua-coat: new package
lua-coatpersistent: new package
lua-messagepack: new package
lua-csnappy: new package
lzlib: new package
lunit: new package