Added set.c to CMakeLists.txt
Merge pull request #185 from matthiasbeyer/add-set_c_cmakelists_entry

Added (missing) entry for set.c in CMakeLists.txt
Add cleared pages between sections
Merge pull request #188 from neithernut/add-paper-emptypages

Add cleared pages between sections
Do not return NULL if node may be point to data