Ignore execve syscalls with no EXECVE message, v1.6

Also fixes a comment typo
Also enhance the reordering hack to attempt to output single messages
Also disables reordering by default
and finally, enable ignoring these execve syscalls with no EXECVE message by default.

See source code for more information on why this is done.

compilation:
make REORDER_HACK=1 (for the reorder hack..)
make IGNORE_EMPTY_EXECVE_COMMAND=0 (to disable empty execves, you'll have an empty summary field in the json message for
these)