[Feature] Multiple accounts

[calendulish]

• [x] stlib support (stlib@utils.py#L118)
• [x] ensure multi-login core concept is usable
• [x] minimal CLI save/load login on multiple http sessions
• [ ] minimal GUI implementation
• [ ] full CLI implementation
• [ ] full GUI implementation with detailed settings

[calendulish]

for CLI:

• would a curses interface be useful at this point?
• if not, what to do with the timed output when using multiple accounts?

for GUI:

• we must have a setting to set default enabled users (similar to --user)
• when the new login info should be requested? must be done sequentially like the CLI