Fix OS/2 support in the smartmontools

[Alex Samorukov]

Current status:

1. Smartctl 5.37 is distributed within system (eCS 2.2). It is compiled by IBM VAC compiler according to the version info (i386-pc-ibmvac)
2. Files os_os2.{cpp,h} were never properly integrated to the release and are missing in the autoconf and resulted targz. This should be easy to fix.
3. File os_os2.cpp is very outdated and currently not compiling properly. It seems that it will need some efforts to compile.
4. Smartmontools itself compiles under GCC/OS2 with some minimal autoconf tweaks and blames that application is not ported. Because of 2.

Todo:

1. Include os_os* to the official tarball, and patch configure.ac and related files.
2. fix os_os2.cpp to make it compile.
3. Test it on VPC (at least -i should work)
4. Ask someone to test it on a real hw.
5. Update man and wiki

[Alex Samorukov]

Fixed in r4421:4423

[Alex Samorukov]

OS/2 version could be found @ ​http://hobbes.nmsu.edu/h-search.php?button=Search&key=smartmontools