Lock and Stake _time parameter is confusing

[3esmit]

_time parameters can be used differently, depending on how current account state is.

After refactor _time become relative.

1. If account state is not initializated, or not locked, executes account.lockUntil = block.timestamp + _time.
2. If account is locked, _time executes account.lockUntil += _time

For both, _mintIntialMP would use _time.

Previously before refactor (#63) _time was absolute, therefore account.lockUntil = _time, and checks were done to ensure this parameters was within boundries of block.timestamp, and _mintIntialMP would use deltaTime = _time - block.timestamp

[3esmit]

I changed to time be relative together with the initialization of accounts based on lockUntil.

Unlocked accounts basically are accounts that lockUntil the exact same time they deposit, so the _time for locking is the block.timestamp of the transaction that initialized the staking.

Therefore, if an account have a lockUntil == 0, this means this account is not initializated, because timestamp 0 is an invalid timestamp value, therefore this value was used to determine initialization of an account.

Previously the refactor, the _time was absolute, this means that the parameter was exact timestamp of lockUntil. and therefore the parameter could be considered _lockUntil. Or it could be zero, that would use _lockUntil as block.timestamp.

After the refactor, the amount of seconds to increase, relative from:

• block.timestamp if blockUntil < block.timestamp;
• else relative from blockUntil.

[3esmit]

I favour the use of relative time, because:

• 0 means 0 time to increase, not a wildflag.
• its easy to determine behavior:
  • users can't set exact input of account.blockUntil;
  • if a condition this, else this.
  • _time value set exact input of _mintInitialMP()

[0x-r4bbit]

There's a chance that changes done here are related to #80
@3esmit do you think we can get your _time related changes in?

If you confirm it's this commit introducing the necessary changes (c12d1ee), we can cherry-pick it.