issue #308. 

Added an option not to append newline automatically when using a custom log formatter. 
Added this both to DDFileLogger and DDTTYLogger since there is no common superclass of just these 2. These change does not make sense for asl logger or any db loggers probably. 
The default value for this feature is to behave as previosly, so this should be backward compatible and not break any library clients that do not use this new behavior. 
We should merge those `if`'s.

Also for performance try to set them in an order such as in most cases not all the conditions will need to be evaluated. Removing parentheses where possible also helps.