I reduced the header includes a lot in Titanic.h and forward
declared when I could. Titanic.h was including a lot and
a lot of functions that were including it were not using its
API. This will help make it more clear which implementation
files are using which class since they will just need to include
which ones they need.
I also moved the debug related items in Titanic.h into the debugger
header.
I also reordered several of the the header includes to be local to
global.
