* Add storageCopy(), storageMove(), and storagePathSync().
* Separate StorageFile object into separate read and write objects.
* Abstract out Posix file read/write objects.
Mainly this helps with unit tests that need to do log expect testing. Add harnessCfgLoad() test function, which allows a new config to be loaded for unit testing without resetting log functions, opening a log file, or taking locks.
Move command begin to C except when it must be called after another command in Perl (e.g. expire after backup). Command begin logs correctly for complex data types like hash and list. Specify which commands will log to file immediately and set the default log level for log messages that are common to all commands. File logging is initiated from C.
