Thankyou so much for the fast response and helpfulness!
I have successfully compiled and installed libninjam, the server and curses client.
Unfortunately I've ran into another error when compiling gninjam; something to do with gconfmm.
http://pastebin.ca/255513
I have gconfmm-2.12.0 installed.
On a side note, I had to install an older version of gtkmm in order to get ./configure to complete successfully. I already had gtkmm-2.8.3 installed but ./configure didn't want those libraries.
So I have gtkmm-2.2.12 installed in parallel. Is this expected and normal?
Many thanks for your help again!