adapted dovecot cfg file path to /etc/dovecot
openfiles-max optimization for dovecot
change openfiles-max during install
check and increase kern.maxfiles
PDO for accessing databases in PHP (rcube >0.9)
added Synchro's option to switch to another devel branch
Update user.rb

fix new user creation issue
Synchro's direct version install for packages. Less choices during install (only  postfix)
reboot cmd enabling higher openfiles limit for Dovecot (hope tmp solution)
Ghraham&Synchros's ssl security nginx update
cmd line openfiles tweeks disabled (ulimit -Sn)
Update 20_install_etc.sh
Merge remote-tracking branch 'upstream/devel' into devel