Server:
- Add GETKEYS: Can fetch all subkeys to a given root key in quick succession.
- Fix critical bug that caused .store files to get corrupted.
- Add cyon_time_us() (time in microseconds).
- Change meminuse to u_int64_t.

CLI:
- Remember this cli is just a test tool and not suitable for production.
- Added test command to fill database with 1000000 test entries.
Merge remote-tracking branch 'origin/master'