Lots of monster stuff, particularly documenting monster abilities

- Monster radiate abilities can now specify a spell pattern to use
- Fix some abilities being incorrectly shown in the editor's ability details dialog (for example, radiate abilities were shown as "Summon aid")
- Add the recently-added monster missile types to the options offered in the editor
- Fix chance of activating not being editable for the martyr's shield ability
- Show the monster summoned for summoning abilities (finally!)
- Show the subcategory for unusual abilities (one of active, passive death)
- Fix the displayed percentage chance for summon abilities (the permille was shown instead)
- Fix incorrect action point display in the editor for the two recently-added monster missiles
- Fix crash when editing a missile ability
- Fix abilities page not showing the newly-added or recently-edited ability after exiting the detail/option dialog
- Fix pick monster button for summoning abilities being off by one

doc/editor/Graphics.html

@@ -39,6 +39,14 @@ contains slots 0 to 9 (numbered left to right), the second row contains slots 11
 and so on. Each sheet contains 100 slots; thus, slots 0 to 99 are on sheet 0, slots 100 to
 199 or on sheet 1, and so forth.</p>
 
+<p>If you don't like having to do the calculations to figure out which graphic is in which
+slot, select Classify Custom Graphics from the Scenario menu, and go through your custom
+graphics, telling the editor what purpose each one is intended for. If you want to use a
+single graphic for multiple purposes (eg, an item and a monster), you'll still have to
+occasionally calculate a graphic number, but by classifying them here, they'll
+automatically show up in all the usual Choose Graphic lists, after all the preset
+graphics.</p>
+
 <h2>How to Make Your Custom Sheets</h2>
 
 <p>Make your graphic in a painting program, and save it as 8-bit PNG (both indexed and RGB