Import of v2

   * Configuration file changed (use libconfuse now)
   * Path to the database configurable
   * Path to the log file configurable
   * Planned LDAP backend for authentification
   * More cleanness in design
Force C99
Code clean-up in aux.c
Remove commented code and use defines
Free the list before quit
Correct register

   * Replace the HOME environment variable at login-time.
   * Correct the path handling when registering new user.
Remove a debug message()
Take options.o_log in account
Add a new features: scriptable filters for name.

At every login exec the scripts at /etc/crlserver/filters/ and refuse
every name that return an error.
Also update README
Clear the screen before fork