move from sql class from mysql_*() to PDO
change PDO error mode for easier debugging during transition to PDO

Note: The error mode will be set to ERRMODE_SILENT after the
      transition to PDO is complete.
PDO for news.php and searchfunctions.php + fix in class sql
fix error due to missing bracket in searchfunctions.php
PDO for cookielogin.php + indexfunctions.php
PDO for functions.php
PDO for applets
PDO for admin scripts, part one
PDO for admin scripts, part two
a bit of PDO
PDO for some more files in data/
more PDO stuff
more PDO stuff for admin scripts
some more PDO for admin scripts
even more PDO stuff

(I need more creative commit messages, this will not be the last
 PDO commit.)
more PDO instead of mysql functions
more PDO for admin scripts
more PDO, part 18
remove some savesql() calls in favour of prepared statements
remove some sql class function calls in favour of PDO calls