version 2.6.4
tag v2.6.3 release
v2.6.2 released 2016-10-24
Tagged version v2.6.1 release
flex v2.6.0 release
mention flex 2.5.39 release in NEWS file
increment version to 2.5.38
flex release 2.5.37
fix call to version in manual
add date of release