(info, html): Implement.

(all): Depend on info.

Flatten info directory.  This undoes the move to one subdirectory per
chapter, which was done during Empire 2.  The structure doesn't buy us
much, as the info name space is flat, and it complicates makefiles.

Overhaul info.pl:
- It now wants to run in the root of the build tree.
- Information on source files and subjects is now stored in makefiles,
  thus info.pl no longer picks up random junk from the file system.
- Clean up Perl anachronisms, in particular use subroutine arguments and
  results rather than global variables where convenient.
- Change format of diagnostics to the common format used by GNU tools,
  so that Emacs and the like can parse it.
- Catch missing .SA.
- When creating a new subject file, cowardly refuse to overwrite an
  existing file.
- Subject files contain topics sorted by chapter, then by name.  The
  order of chapters used to depend on how Perl sorts hash keys.  Fix
  it.

info/Taxes.t

@@ -0,0 +1,36 @@
+.TH Concept Taxes
+.NA Taxes "How taxes are calculated"
+.LV Expert
+.s1
+Civilians exist in Empire to work and provide cash to the government.
+Simply by existing,
+they generate revenue to their host country
+in proportion to the efficiency of the sector
+in which they work.
+.s1
+The military-industrial complex exists
+in order to siphon off hard-earned tax dollars.
+Military cost (in general) about ten times as much
+as a civilian pays in taxes.
+.s1
+In addition, \*Qfinal goods and services\*U cost money to produce.
+Ships, land units, planes, guns and shells are all examples of the costs
+inflicted upon a helpless government by the military-industrial complex.
+Also, \*Qservices\*U such as technology research, medical research,
+and even happiness (money and lcm's can buy happiness here...)
+cost something to create.
+Consumer items such as food, lcm, hcm, and all other \*Qintermediate
+goods\*U (or raw materials) cost nothing other than the hard work of
+the oppressed citizenry.
+.s1
+Note that it takes ten civilians to keep one soldier in the field.
+Note also that the only way to make money is either to be pacifistic
+and let your nation accumulate wealth by having a small standing army,
+or by selling products to other nations. Also, land units can multiply
+the strength of each mil, making them perhaps more economical, if you
+already have made the technological investment.
+.s1
+Also note that captured civilians only pay 1/4 the normal taxes.  They
+like to hide money until they are all finally agree to become naturalized
+citizens of their new government. 
+.SA "Updates, Nations"