Tech-demo combo system, and some other things.

Tech-demo combo system, and some other things.

* core.hh: New command CMD_POWER_ATTACK, and some Doxygenation.
* default.permobjs: All weapons now flagged melee or ranged.
* monsters.cc, monsters.hh: Elimination of newsym() calls and addition of new
  functions to adjust flow of updates.
* notify-local-tty.cc, notify.hh: New notifications galore.
* permobj.hh, pobj_comp: New item flags
* player.hh: new boolean functions for examining player's wielding status
* u.cc: Action rewriting system with tech-demo combo detection case.

Sir Not Appearing In This Commit: Making a power attack be an actual thing
instead of just an ordinary attack.