Cities generate science at 50%, research happens automatically

[QuintillusCFC]

This is the first tech card, designed to be the bare minimum for tech to progress (but not have all its effects).

Cities generate research. Initially always 50% of their commerce output (no slider adjustments yet). TBD if that is rounded up or down (if it generates 3 commerce, does it give 1 or 2 to tech?).

Each civ keeps track of which techs they know. They choose techs randomly from among those that they are able to research. Need to have a method to keep track of which ones are available to research, maybe that is a different card.

As part of post-turn processing, advance the progress on finishing research, and if appropriate mark it as done and select a new one.

Show the tech being researched in the lower-right, with an estimate of how many turns are left.

[lexer-gamedev]

I'd like to implement this. Seems easy enough.

[esbudylin]

@lexer-gamedev It looks like it's already implemented in #529

[TomWerner]

@lexer-gamedev there's still lots of interesting tech-related stuff that can be done if you're interested.

The next tech steps have a mix of difficulties, and many of them are independent:

• displaying unit icons unlocked by a tech (and allowing them to be built)
• displaying building icons unlocked by a tech (and allowing them to be built)
• figuring out how to pick which of the tech textures to use depending on the number of icons to display (there's a todo for this in ScienceAdvisor.cs
• connecting resource visibility to techs (like only showing iron after iron working)
• adding a simple AI player tech picker, which could be hardcoded or random to start
• importing the "not needed for era advancement" signal from the biq files in ImportCiv3.cs
• displaying the "not needed for era advancement" signal in the science advisor ui
• implementing era advancement
• adding a popup for tech selection, right now it can only be done via the science advisor
• properly displaying gold per turn in the right hand corner ui
• improving the domestic advisor so we can see the effect of moving the science slider

[TomWerner]

#528 also added two TODOs to C7Engine/EntryPoints/TurnHandling.cs that are somewhat related to science, those should be pretty simple to address.