Merge branch 'HealBalancing' into 'master'

Heal Scaling Update

Various adjustments to healing/anti-healing debuff balance for the changes to healing_factor from increased Constitution.

Moved callbackOnHeal callback trigger to beginning of Actor:onHeal.  This allows callbacks to trigger correctly before Bloodlock and Solipsism are checked and sort themselves with callback priorities.

Added documentation to the callback control functions.

Adjusted healing_factor bonus for improving Constitution (limited to +150%), to match limit scaling of anti-healing debuffs and prevent runaway healing effects on high level randbosses.

Talent Changes:
One With Nature: Fixed cooldown.  Slow scaling of nb of infusions affected (small nerf) and cooldown adjustment (small buff at low talent levels).

Healing Nexus:  Converted to use callbackOnHeal (with high, -5, priority).  Rescale radius and equilibrium gains.  Duration (<20 turns) and percent heal stolen (<100%) have reasonable limits.  Heals stolen are based on the raw heal value (no compounded healing_factor effects).  Debuff is applied only to others, while a buff is applied to the user (fixes interaction with buff/debuff affecting abilities).  Buff improves all healing received by up to +100%, instead of creating a new heal so equilibrium is only gained once per heal stolen.

Healing Inversion: Conversion to Blight damage uses raw healing value, triggered after (most) other healing effects (callback priority +1).

Bathe In Light: healing buff limited < + 100%.

Poison Storm: Insidious Blight healing penaltiy limited (to -150%), Crippling Blight fail chance limited (to 50%)

Epidemic: healing penalty buffed (to -150% healing)

Insidious Poison: healing penalty buffed (to -150% healing)

Slash: healing penalty buffed (to -150% healing)

Bleeding Edge: healing penalty buffed (to -150% healing)

Golem Resilience: healing_factor buff limited to +100% healing

Unstoppable: Buff sets the "no_healing" attribute, description clarified.

Throwing Knives: Fix talent learn/unlearn abuse

INSIDIOUS_POISON damage type: has built in healing_factor limit (to -150%).

HEALING_POWER damage type: has built in healing_factor limit (to +100%).

BLIGHT_POISON damage type: has built in limits for effects set:

	INSIDIOUS_BLIGHT: healing_factor (to -150%)

	CRIPPLING_BLIGHT: fail chance (to 50%)
	
RANDOM_POISON damage type: has built in limits for effects set:

	INSIDIUS_POISON: healing_factor (to -150%)

	CRIPPLING_POISON: fail chance (to 50%)

	NUMBING_POISON: damage penalty rescaled (0.75 power)

	
Evisceration weapon ego:  Bleeding damage and healing penalty take weapon skill into account.  Healing penalty limited (to -150%).  Effects displayed in object description.

Barbed ammo ego:  Bleeding damage and healing penalty take weapon skill into account.  Healing penalty limited (to -150%).  Effects displayed in object description.


Misc:
May leave the level immediately after a kill in developer mode.

See merge request !388