Add geodate command

[vinc]

Geodate displays the current local time in a geocentric date format using a natural lunisolar calendar with metric time based on decimal fractions of the mean solar day.

https://github.com/vinc/geodate

[vinc]

Some errors are still encountered while compiling the crate:

rust-lld: error: undefined symbol: fmod

And:

rust-lld: error: undefined symbol: __truncdfsf2

[vinc]

The issue above is no longer happening:

~
> geodate -3.3333
01:23:12:01:97:18

I can now run geodate inside the OS!

Next step would be to run it from userspace to produce a external binary instead of including it in the kernel.

[vinc]

Not quite there yet:

~
> geodate -3.3333
DEBUG: EXCEPTION: GENERAL PROTECTION FAULT
DEBUG: Stack Frame: InterruptStackFrame {
    instruction_pointer: VirtAddr(
        0x444445649104,
    ),
    code_segment: 43,
    cpu_flags: 0x206,
    stack_pointer: VirtAddr(
        0x444445e3ec38,
    ),
    stack_segment: 51,
}
DEBUG: Error: 0
DEBUG: panicked at 'explicit panic', src/sys/idt.rs:136:5