collect: Derive collection value from power value

collect: Derive collection value from power value

The collection value of a sector is

    sector value = sector type value * (sector efficiency + 100)
                 + sum of item values
    item value = item type value * amount

The sector and item type values are configurable.

The item type collect values aren't too far off the power values:

    uid mnem  pow val pow/val
      0  "c"   50   1   50
      1  "m"  100   0  inf
      2  "s"  125   5   25
      3  "g"  950  60   15.8
      4  "p"    7   4    1.75
      5  "i"   10   2    5
      6  "d"  200  20   10
      7  "b" 2500 280    8.9
      8  "f"    0   0  NaN
      9  "o"   50   8    6.25
     10  "l"   20   2   10
     11  "h"   40   4   10
     12  "u"   50   1   50
     13  "r"   50 150    0.33

The power value is very roughly ten times the collect value, except
for civilians and uw it's 50, for rads its 0.33, and military are free
to collect.  The latter two make no sense.

Replace the item type collect value by the power value / 50 for
people, and by the power value / 10 for everything else.  This makes
collecting military, shells, guns and uw more expensive, and petrol,
bars, iron, oil and rads cheaper.

The sector type values are basically arbitrary.  For instance, an iron
mine costs five times as much as a wilderness, but a third of an
uranium mine, regardless of actual resource contents.

Replace this by different arbitrary values:

    sector value = (item value of materials necessary to build it
                    + build cost) * efficiency / 100
		 + sector type maximum population
                 + sum of item values

Some sector types become cheaper, some more expensive.

Drop sect-chr and item selector value.

Signed-off-by: Markus Armbruster <armbru@pond.sub.org>