relicense module 'group-member'

[Bruno Haible]

Hi Jim, Paul, Eric,

You are the contributors of the module 'group-member', which is under GPLv3+.
Can you agree to relicensing it under LGPLv2+?

Rationale:

The 'euidaccess' module, which is under LGPLv2+, needs to use this module
(for portability to many platforms). Currently gnulib-tool emits a warning
about the license mismatch:

  gnulib-tool: warning: module euidaccess depends on a module with an 
incompatible license: group-member

The first obstacle to fix this was done by Paul on 2012-10-22, when he replaced
uses of xmalloc() with malloc().

The remaining obstacle is simply the approvals of the contributors.

Bruno