Update ADOdb to v5.18a (released 6 Sep 2012)

Changes vs upstream release[1]:

 - removed following dirs and files:
   contrib/ cute_icons_for_site/ docs/ pear/ tests/ server.php
 - converted CRLF to LF
 - trimmed trailing whitespace

[1] http://phplens.com/lens/lensforum/msgs.php?id=19268

Fixes #13713, #14398