clean up directory and quoting styles in #include lines

source/texk/web2c/luatexdir/image/epdf.h

source/texk/web2c/luatexdir/image/image.h

source/texk/web2c/luatexdir/image/writeimg.c

source/texk/web2c/luatexdir/image/writeimg.h

source/texk/web2c/luatexdir/lua/lepdflib.cc

source/texk/web2c/luatexdir/lua/limglib.c

source/texk/web2c/luatexdir/lua/luagen.c

source/texk/web2c/luatexdir/lua/luatex-api.h

source/texk/web2c/luatexdir/lua/texluac.c

source/texk/web2c/luatexdir/ptexlib.h