RFR: 8031669: (xs) Allow override of "simple required tools" in basics.m4

[Mike Duigou]

Hello all;

This changeset allows overriding of the "simple required tools" which are gathered in BASIC_SETUP_FUNDAMENTAL_TOOLS macro of basics.m4 I didn't extend the override ability to every tool, instead primarily to the file manipulation and archiving tools which I need to override for a project I am working on.

http://cr.openjdk.java.net/~mduigou/JDK-8031669/0/webrev/

Mike