libcommon utilities supply project

- Add precise main page documentation with library architecture
  : In order to create a real architecture description documentation

- rename libstring pathcat() function. Purge ustrcpy & ustrcmp
  which is not used and not sain.

- finish man pages for libstring.

* finish the cm_getopt test file in order to check its behaviour with new
* simplier API

! Add syslog facility API in libdebug
