* change miscellaneous things to more idiomatic zig style
 * change the digest length to 24 bytes instead of 48. This is
   still 70  more bits than UUIDs. For an analysis of probability of
   collisions, see:
   https://en.wikipedia.org/wiki/Universally_unique_identifier#Collisions
 * fix the API having the possibility of mismatched allocators
 * fix some error paths to behave properly
 * modify the guarantees about when file contents are loaded for input files
 * pwrite instead of seek + write
 * implement isProblematicTimestamp
 * fix tests with regards to a working isProblematicTimestamp function.
   this requires sleeping until the current timestamp becomes
   unproblematic.
 * introduce std.fs.File.INode, a cross platform type abstraction
   so that cache hash implementation does not need to reach into std.os.