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

o Add syslog facility API in libdebug

- In order to have a correct coverage testing
  check the different test_* files links to only the tested lib, not all libcommon

- Problem of dependency between tests & updated libcommon
  when updated the sources and recompiled one of he libcommon part, the tests
  are not recompiled in order to get back the modification

* Add libdebug manpages
