(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/convert.t

@@ -0,0 +1,40 @@
+.TH Command CONVERT
+.NA convert "Change conquered civilians into uncompensated workers"
+.LV Basic
+.SY "convert <SECTS> <NUMBER>"
+The convert command converts \*Qenemy\*U (captured) populace into
+uncompensated workers.
+If the sector is not actually conquered, no civilians will be
+converted.  If you convert all the civs in a sector, then the sector
+is no longer occupied (i.e. you become the "oldowner" of the sector).
+.s1
+After the program has collected any necessary information
+it will list each sector where civilians are converted.
+.s1
+Note: you must have enough military in the sectors to force the 
+populace to become uncompensated workers -- about 10%. Land units
+count toward this at a value equal to the number of mil required
+to build them. Security units are even more efficient, counting for
+more than their base value, and increase the number converted.
+.s1
+There must also be mobility in the sector to be converted (see \*Qinfo
+Mobility\*U for the exact formula).
+.s1
+.s1
+.EX conv -3:3,-1:2 10
+.NF
+Number to convert : 22
+ 22 conquered populace converted in -1,-1 (30)
+ 13 conquered populace converted in 1,-1 (13)
+ 22 conquered populace converted in 3,-1 (30)
+ 17 conquered populace converted in -2,0 (17)
+ 22 conquered populace converted in 0,0 (36)
+ 22 conquered populace converted in -1,1 (34)
+ 22 conquered populace converted in 1,1 (34)
+ 18 conquered populace converted in 0,2 (18)
+ 22 conquered populace converted in 2,2 (45)
+Total new uw : 180
+.FI
+Note that there is a cost of 0.01 BTU's per civilian converted
+in addition to the registration fee of $1.5 per conversion.
+.SA "Populace, Mobility, Occupation"