the libiconv that was available for R5
* cleaned up iconv.h
* moved public libiconv headers (iconv.h and localcharset.h) into a
specific folder in headers/libs
* renamed config.h to libiconv_config.h in order to circumvent strange
problems with regex.c from glibc picking it up
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@28630 a95241bf-73f2-0310-859d-f6bbb57e9c96