promote event logging to stable

allow use of the log function in stable mode as well as alpha
and beta
Remove definitions of Schemas (code health)

    Put them in a config file instead.
    See:
    https://gerrit.wikimedia.org/r/48060

    Change-Id: I67d59999cbb83e9a2d66282cf65017b8e9a8878d

Change-Id: If334da5705c7000b4d1b5375cff8f971cde187a1
Merge "promote event logging to stable"