Add **many** things (refactor core, add cache, ETA, multiple password file options, ...)

[synacktiv-antoineg]

for another day

[knavesec]

@synacktiv-antoineg Any particular reason you closed this? Looks really interesting on face value

[synacktiv-antoineg]

@knavesec Yes, the code was not reviewed and field-tested enough internally by my company, so we decided to postpone the PR in order to serve better quality code. I will re-open it soon