==== GREED SKILL SYSTEM

=== do_practice

*	can practice if ch->pcdata->learned[sn] >= 1.

*	can spend only one practice on do_practice() like on SMAUG.
	if ( ch->pcdata->learned[sn] >=
				class_table[ch->class]->skill_adept * 0.2 )

*	check_improve() only works if ch->pcdata->learned[sn] > 1;

=== do_gain

*	10 pracs => 1 gps.

*	20 pracs => ch->points -= 1.

*	10 * group_table[gn].group_rating[ch->class] pracs => gain 1 new group.
*	10 * skill_table[sn].skill_rating[ch->class] pracs => gain 1 new skill.