[ccache] effect upon ccache of changes to cache_dir_levels

[Scott Bennett]

     What does ccache do to an existing cache tree if one increases
or decreases the value of cache_dir_levels in ccache.conf?  Are cache
entries moved?  Are directories added or deleted to accommodate the
change?

                                  Scott Bennett, Comm. ASMELG, CFIAG
**********************************************************************
* Internet:   bennett at sdf.org   *xor*   bennett at freeshell.org  *
*--------------------------------------------------------------------*
* "A well regulated and disciplined militia, is at all times a good  *
* objection to the introduction of that bane of all free governments *
* -- a standing army."                                               *
*    -- Gov. John Hancock, New York Journal, 28 January 1790         *
**********************************************************************