Use array instead of long switch for faster compilation

The long switch in src/hnc2unicode.c just makes compilation slow
uselessly. It does not reduce the size.

Convert the very long switch into a array for faster compilation. And
move array data in src/hnc2unicode.h to src/hnc2unicode.inc.

Add AC_PROG_CC_C99 in configure.ac, because designated array
initializers needs C99.
Merge pull request #9 from changwoo/misc-fixes

Use array instead of long switch for faster compilation
Merge branch 'master' into experimental
update THANKS
Merge branch 'master' into experimental
fix segfault (closes #13)
Merge branch 'master' into experimental
add src/hwp2pdf.c
update
add hwp2pdf.c
fix warning
update
update
add unhwp (hwp v5 extractor)
add hanword_version
fix some bugs
fix typing error
fix unexpected exit
add AM_PROG_CC_C_O
add variable: layouts