complibs: introduce generic multi-complibs infrastructure

Use the same method as companion tools for providing generic and
extendable companion libs.

Signed-off-by: Yann Diorcet <diorcet.yann@gmail.com>
Message-Id: <515c5c4635d99ebe4877.1353074410@macbook-smorlat.local>
Patchwork-Id: 199613

 This is NOT the official version of dialog.  This version has been

 significantly modified from the original.  It is for use by the Linux

 kernel configuration script.  Please do not bother Savio Lam with 

 questions about this program.