Better use of wifi and time configuration

[baronunread]

I've been hard at work but this is a possible way to make this entire system last a bit longer than what it does currently. There's some missing features for sure but I'll work on it some more when I do have the time.

With this fork I've added:

• wifi connection on init and setting time there only if it's available which solves Enable wi-fi and set time only on INIT or user input #6
• configurable battery maximum and minimum values for the current voltage in os_config.h to get an idea of where the battery percentage it's at. Also added a charging state with a charging icon. Solves More precise battery percentage #7 and If charging don't deep sleep #8
• most of the logic that was being repeated many times over and over again (wifi and RTC) is now set only on INIT and then it's saved and reused. There's a save also in the preferences on every light loop just in case something goes wrong. Solves Not using RTC getLocalTime after using configTime #5
• added backup wifi SSID and PASSWORD in os_config.h to handle the problems of Connecting to WiFi #1 which I still haven't resolved.

Not everything will fit with your vision and that's fine, send me some comments if you'd like

@qewer33 now for a personal message to you: I've been working on it because I fully believe that there's so much more to this and the design and idea are just fantastic. We can definitely squeeze a lot more from this so I hope at least in some way I reignited your passion about it :)

[baronunread]

I don't want to modify the os_config.h all the time before committing I'm making an empty one and an example

[qewer33]

Hey! Thank you for the PR, and about the message, I've kinda moved on to other stuff and projects these days so I'm not sure if I will be able to continue working on qpaperOS that much. You are definitely better off just maintaining your own fork (and if you're committed to actively develop it for some time, I can put a redirect to your fork on top of the README :D).

Also as a review for this PR, you should probably not untrack os_config.h since the firmware will not compile without it + it's good to provide a default config.

[baronunread]

Ah yeah I figured I messed up when I untracked lol
I added it back in and did this command git update-index --assume-unchanged src/os_config.h

Thank you for your time and for the offer, if you think it's a worthy successor to your work then I'be quite happy and will continue to nibble on it little by little. Are you still using the watch? I was thinking of adding the missing features (minus the GPS, that would really be a battery hog so I didn't get that model haha!)