bitcoin/bitcoin — pull request #4832 by TheBlueMatt (2014-09-03 10:09:08+00:00)
Title: We list X11, but are actually expat...switch to X11 for consistency

Justification for this being OK:

As X11 is strictly more restrictive, and things can be relicensed
under a strictly more restrictive license, we can clear up the
uncertainty with this commit without needing callbacks from everyone
defined under "The Bitcoin Core Developers".