Replaced console logging with SLF4J

[pards]

No description provided.

[coopernurse]

Looks good. There's a few minor aesthetic things to look at:

• tabs vs spaces -- the indentation in some of the java files isn't consistent
• LOGGER vs logger -- I'd suggest picking one naming convention

[pards]

Thanks James.

I'll fix the tabs vs spaces.

LOGGER vs logger - the former is the static variable, the other is an instance variable. For consistency I'll make them all static and go for the uppercase naming.