Building on OpenBSD - make should be gmake

[rapenne-s]

On OpenBSD (and certainly on DragonflyBSD and NetBSD), binaries aren't distributed so the compilation from sources must used to get the binary.

The issue is that make used in the process is using the make from system which is bsd make. The gmake binary should be used instead of make.

[rapenne-s]

A hack to solve the issue without fixing every dependency with this issue is to create a ~/bin/ directory and create a symbolic link named make to /usr/local/bin/gmake and add this path into $PATH