Improvements

[awnumar]

• [x] Improve docs.
• [x] Rename GenKey to NewRandom.
• [x] Only execute permissions functions if permissions are changing.
• [x] Rename DisableCoreDumps to DisableUnixCoreDumps.
• [x] Add tests for Once property of CatchInterrupt.
• [x] Allow New functions to create LockedBuffers with alternative permissions.
• [x] Add function to return pointers to every non-destroyed LockedBuffer.