Allow installation as unprivileged user

[mobstef]

I have prepared a patch for Makefile to resolve two issues I have hit when preparing FreeBSD port of OSSEC:

1. The "/etc/localtime" is required to exist during installation process. It is copied to OSSEC "etc" directory. The question is why? Shouldn't it be copied at runtime in case it has changed after OSSEC installation? Anyway I still need to assume it may not be present during build on FreeBSD build servers. I have introduced a flag "INSTALL_LOCALTIME" set to "yes" by default. I just invoke "make" with the flag set to "no". In FreeBSD port the "/etc/localtime" will be checked for existence and copied during OSSEC startup.

2. The FreeBSD build servers create binary packages from ports as non-root user. It is therefore essential, that the Makefile allows installation as non-root user too. The problem with current Makefile is that it explicitly references "root" user and "0" group. Additionally it sets permission on certain directories to 550 and later writes to them, which is possible by root, but not as an unprivileged user. The best solution I came up with is to replace every invocation of "install" command by a macro, that by default sets mode and ownership of files as it used to be ("INSTALL_CMD"). If anybody needs to skip permission and ownership setting, he just need to set "INSTALL_CMD=install".

I am of course open to discussion on the topic, but will be extremely glad to see it resolved for the next release after 3.1.0. The patch is for 3.1.0.

patch-src_Makefile.txt

[ddpbsd]

1. Seems reasonable. Probably just something in the ossec-control script? I'm not sure how this would affect systemdOS though.
2. If I can ever get it to apply, I'll try it out.

[ddpbsd]

I opened pull request #1599 with your patch. Thanks!