Fixes "warning: null argument where non-null required" compiler warnings by not passing NULL to strdup and "(warning) Conversion of string literal to bool always evaluates to true" found by cppcheck.
Fixes several "(style) The scope of the variable 'p' can be reduced" found by cppcheck.
Used codespell -w.
This way, users need only type "make" to build instead of needing to "cd wmppp" first.
