Fix a bug that caused the net food display to be incorrectly colourized.

* The prettified value isn't a number anymore, so one must use the
pre-prettified value for calculations.
Dynamically generate the building controls.
v1.1.13: A number of minor UI and JS tweaks.

Moved the free land display to be near the building panel.
Moved the morale display to be near the population panel.
Removed the panel subheadings.
Fix the dynamic cost updates broken by 1.1.12 changes.
More misc. JS cleanup.
v1.1.13: Use an O(1) equation to calculate worker food costs.

- This should be much more efficient than the old iterative method.
- Also calculate all costs to full precision, without rounding.
Implement spawn/raise Max.

Also:
- The 'Max' buttons operate in O(lg(n)) time, which should be
acceptably responsive)
- Corpses are now treated as a resource, rather than a population unit.
Unfortunately, this slightly breaks compatibility with prior versions;
v1.1.13+ will load prior save games, but prior versions will lose their
corpses if they try to load a v1.1.13+ save game.
- Moved the displays for happiness, free land, and zombies to be in more
useful places.
- Removed the panel subheadings; they were taking up space, and not
conveying useful information.
- All costs are now calculated to full precision, although the display
is
rounded to the nearest integer. Button emable/disable is also now
performed on the unrounded values, so users may occasionally see that
button enable/disable effects are not perfectly synchronized with the
number displayed. This is because the enable/disable uses the exact
value, whereas the number displayed rounded first.
- Fix the dynamic cost updates broken by 1.1.12 changes.
- Fix the background so it stretches to cover again.
- Raise Dead buttons now enable and disable properly.
- Replaced the worker and zombie cost iterative calculator with a
constant-time formula version. This should improve responsiveness
with large numbers.
- Consolidated all of the assorted hire/fire functions into one.
Add xmlns.
Switch <b> tags to <strong> per HTML style recommendations.