Fixed bugs found in review of commit 46ee9e4476e48a7f7b453dd6f8629032de9c6733
Merge pull request #9 from jap/master

OS X compilation fixes
Fix linux/gcc compilation using ugly #define hack
remove include of net/if_ppp.h, as it does not exist on OS-X
merge in misc.h fix
use %zu for size_t, fixing warnings
Provide a definition for ETH_P_PPP_SES to make it compile on OS X even better!
Also provide an alternate implementation of basename so all demonstration tools compile on OS X.