Updated CHANGES file

Fixed the calculation of the keyframes for audio only files

Updated the changes for 1.7

Updated the list with the changes in 1.6

Bumped version number to 1.5

1.4 release (importing all recent releases)

1.3 release (importing all recent releases)

1.2 release (importing all recent releases)

1.1 release (importing all recent releases)

1.0 release (importing all recent releases)