As part of the CMake port we updated the duration formatting to contain
maximum of 6 decimal places but without trailing 0s. There was a bug
however where it used 6 significant digits rather than 6 decimal places
(`%g` rather than `%f`).
This fixes the bug and also updates the MPD sample files for the
integration tests to contain maximum of 6 decimal places.
The KeySource now only handles fetching the keys and loading any PSSH
info from the license; it will not handle generating new PSSH info
based on the config.
This will allow the PSSH generation to access to the full
EncryptionConfig so we can add additional options to it.
Issue #756
Change-Id: Ia67387aa3d5ec0d723b7f5f21fc517f64c840393