Install default configuration in ${PREFIX}/etc

[DoomHammer]

This patch does two things:

1. It makes ls++ search ${PREFIX}/etc instead of /etc for installation in non-default localization.
2. It installs default configuration in ${PREFIX}/etc so ls++ is usable from the beginning.

As I am not a Perl hacker I understand there might be better ways to do this, so I am open to suggestions.

[DoomHammer]

@trapd00r could you take a look at this?

[trapd00r]

Sorry for the (very) late reply. I've been absent for quite some time for personal reasons.
I like the general idea, but: what happens when you run make install the second time - this looks like your ls++.conf will be overwritten?

[DoomHammer]

You are right. What about the new approach?

[trapd00r]

Looks great, thank you!