Sindbad~EG File Manager

Stuff that needs to get done:

In no particular order, this stuff still needs to be done (or is in progress):

1) file i/o
 a) get an in-memory representation via mmap *done*
 b) render in-memory representation back to disk also via mmap *done-ish*
2) signatures
 a) read hash from stand-alone file *done*
 b) write hash to stand-alone file *done*
 c) verify hash from stand-alone file
 d) read cert from file *done*
 e) create hash/digest of file *done*
 f) create new signature (aka "sign the hash")
  i) generate SpcContentInfo *done*
  ii) sign it *done*
 g) create cert table *done for the very basic (ms-supported) case*
 h) find cert table *eh*
 i) implant cert in table *eh*
3) make hash algorithm configurable
4) test suite
5) test suite
6) docs
7) efikeygen - random serial number + check for dupes against local nss db

See also: https://github.com/vathpela/pesign/issues/milestones