ltj-rmlgbm.lua: "slant=..." and "extend=..." for non-embedded fonts now work again.

ltj-rmlgbm.lua: "slant=..." and "extend=..." for non-embedded fonts now work again.

 * Fonts whose em size is not 1000 is not correctly drawn by LuaTeX.
   (This is not LuaTeX-ja specific;
    see http://oku.edu.mie-u.ac.jp/tex/mod/forum/discuss.php?d=1009)

 * \CID and commit 0c68dbd doesn't work correctly.
   e.g. luaotfload maps "Japan1.668" (fullwidth) to proportional glyph.