• Fix build with libc++ 3.9
• Switch to USES=localbase
• Add LICENSE: GPLv2+ for VBA code, LGPL21 for bundled libresample code and NONE for playgsf code, as no license is specified neither for it nor for code it's based on (http://www.caitsith2.com/gsf/)

PR: 214653
Submitted by: amdmi3
Reported by: jbeich