10/23/2014: There was an error with PHP 5.3 (see comments), which is fixed now.
A new version of the DKIM-Patch for ISPConfig is available now.
Changes to 1.0:
make it compatible with ispconfig 188.8.131.52p4
add backup to install.php
changed regex for private-key
use interface-temp instead of server-temp
allow dkim-strength up to 4096 bytes
allow symlink for amavis-configs (but NEVER for dkim-keys)
fixed issue when a client / reseller uses the dns-wizard
changed amavis.conf.dkim; otherwise in some enviroments the amavisd-config might be corrupted
corrected version-number in the server-plugin