cache db and index directories in env variable on ns_server

to reduce traffic between ns_server and ns_couchdb nodes

Change-Id: If5475c203e26273fe28d1ccefd7e619c3da6e102
Reviewed-on: http://review.couchbase.org/43435
Reviewed-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>
Tested-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>
[MB-12677]: add the abilty to collect host lookup information

cbcollect_info will read the hosts, resolv.conf and nsswitch for
unix systems.

For Windows it will collect just the hosts file as it already
collects the other information.

[alk@tut.by: capitalized Raw]
Signed-off-by: Aliaksey Kandratsenka <alk@tut.by>
Change-Id: I66cb2eda62d485c84fb1c6dab3f1bdbaf66ecaf3
Reviewed-on: http://review.couchbase.org/43330
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>