dovecot:ssl: Add parameters ssl_cipher_list and ssl_prefer_server_ciphers
Add header information for better syntax highlighting
dovecot: Add possibility to overwrite configuration files from package
dovecot::postgres: Add parameter dbport (postgres database port)
dovecot::logging: Add paremter log_timestamp
dovecot::postgres: Make dovecot-sql.conf.ext template configurable
dovecot::mail: Only add user/group, if not already defined
Use defaults from http://wiki2.dovecot.org/AuthDatabase/SQL
Remove duplicate test for 'dovecot-pgsql'
Remove trailing space
Fix some build warnings