With agreement of all contributors, simplifying licensing to MPL2

(cherry picked from commit 6741805f2e98fab62899ebb6776b93d473a2ec94)

Conflicts:
	inc/libcdr/CDRStringVector.h

Change-Id: I7dec727b183d9543cdad67cd9202195cd7370877
Sanitize the README file

Correspond to the new simplified license
Remove the mentions of supported CDR versions in order to be more future-proof

Change-Id: I2d782a61ce938d521fb617744697e81a93dbec40