Adding help text to the options that did not have it.
    
    Many of the config options did not have help text set.  This patch
    adds text for those.
    
    patchset2 adds 5 skipped options
    
    patchset3 adds a missing underscore before the helptext bracket
    
    patchset4 fixes pep8 errors
    
    patchset5 notes the units (seconds) in sql_retry_interval, as noted
    by Flavio Percoco Premoli
    
    patchset6 fixes comments from Alex Meade
    
    Fixes bug: 1162449
    Change-Id: Ic75e499456e389df2ec527594bbcd54c0b464ee3