migrated install-class to new PDO database class, needs testing, refs #1287

Signed-off-by: Michael Kaufmann (d00p) <d00p@froxlor.org>
removed deprecated db-class (mysql-extension) as it is not needed anymore

Signed-off-by: Michael Kaufmann (d00p) <d00p@froxlor.org>
fix wrong parameter-name in admin-customers; check for disabled imap/pop3 when adding mail-accounts as customer, fixes #1298

Signed-off-by: Michael Kaufmann (d00p) <d00p@froxlor.org>
remove not-functional method 'maildirExists' as maildirs have chmod 700, show 'remove files' on overview-delete if mail-address is an account, fixes #1275

Signed-off-by: Michael Kaufmann (d00p) <d00p@froxlor.org>
Merge branch 'master' of git://github.com/Froxlor/Froxlor
Fixed some bugs, made activationcode more secure, added update script, merged missing commit