Doc build schedule

Hi,

Is there any particular reason we only build docs once a week? It may have made 
sense with a previous toolchain, but it takes one minute here to build English 
version of the manual with Phd, so the whole build process (all languages and 
formats) should take (at most) 30 minutes on PEAR website.

One unfortunate commit like http://news.php.net/php.pear.doc/12130 can prevent a 
week worth of changes from going live.