Fix linking error while building it on Fedora17.

Linking CXX executable ../build/wiznote
/bin/ld: CMakeFiles/wiznote.dir/share/sqlite3.c.o: undefined reference to symbol 'dlclose@@GLIBC_2.2.5'
/bin/ld: note: 'dlclose@@GLIBC_2.2.5' is defined in DSO /lib64/libdl.so.2 so try adding it to the linker command line
/lib64/libdl.so.2: could not read symbols: Invalid operation
collect2: error: ld returned 1 exit status
make[2]: *** [build/wiznote] Error 1
make[1]: *** [src/CMakeFiles/wiznote.dir/all] Error 2
make: *** [all] Error 2