General cleanup and optimizations. Some functions are fixed,
some were turned into [const fn], and other small stuff like
[AtomicUnit] using a [u64] instead of a [u128]
user_p2pool_percent = The percent of hashrate the user accounts for
relative to all of P2Pool's hashrate.
user_monero_percent = The percent of hashrate the user accounts for
relative to all of Monero's hashrate.
This adds all necessary functions/conversions/serde/tests for the
new APIs. It also includes the actual reads inside the watchdog loop.
Every loop, [tick] will increment by 1. At [60], the watchdog
will attempt to read and parse the [network] & [pool] APIs.
Since the loop is [900ms], this means this will occur around
every 54 seconds. [tick] gets reset upon successful read/parsing.
