The header of plink.c says it is GPLv3+, the ver_str says it is only
GPLv3. So who is right?
The LPGL license should be for Rconnection.* and not only Rconnection.cc.
plink_glm.c is partly licensed under BSD-3.
plink_ld.c says that credit has to be given to Howey and the license
of his part is GPLv3.
Please update your debian/copyright accordingly.