(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/lload.t

@@ -0,0 +1,46 @@
+.TH Command LLOAD
+.NA lload "Load things onto land units"
+.LV Basic
+.SY "lload <COMMODITY> <UNITS> <AMOUNT>"
+.SY "lload plane <UNITS> <PLANES>"
+.SY "lload land <UNITS> <UNITS>"
+The load command carries out the loading of units.
+Commodities (like guns, civs, food) can be loaded onto any unit capable
+of carrying them (to see what cargos a unit can carry, use the show command). 
+.s1
+Some land units can carry extra-light
+planes (typically these are SAM's)
+.s1
+Some land units can carry other units
+.s1
+.SY "lload <COMMODITY> <UNITS> <AMOUNT>"
+In the first form,
+the amount argument specifies the amount of the given commodity
+you wish to load on each unit specified.
+Amounts greater than that allowed will be truncated to the
+maximum possible. Amounts less than 0 indicate that you want to
+make the unit/army have that amount. If the unit/army has less
+than that amount, more will be loaded. If the unit/army has more
+than that amount, the commodity will be unloaded. For example,
+.s1
+.EX load food 3 -100
+.s1
+will cause unit 3 to load or unload food so that it has 100.
+If it had 120 food, 20 would be unloaded. If it had 50 food, 
+50 would be loaded.
+.s1
+.SY "lload plane <UNITS> <PLANES>"
+In the second form,
+where you say \*Qplane\*U instead of say \*Qciv\*U a plane/missile
+is loaded onto a unit.
+.s1
+See the \*Qshow\*U command for a table of the maximum amounts of
+each items that can be carried on each unit type.
+.s1
+Note that if either <UNITS> or <PLANES> does not start with a
+number (e.g. it is of the form "a" or "*" or "#1" and not of the form
+123 or 12,14) then you will not be given any error messages.  This is
+so that you can type something like "lload plane * *" without getting a
+hundred error messages.
+.s1
+.SA "lunload, Unit-types, Plane-types, LandUnits, Moving"