Additional log entries, increase MP cost of Heal

Entries are now logged at the start of a battle for MP contributed to
the shared pool by individual party members.
Add coloring for elemental damage

Besides making the battle screen more dynamic, this makes it easier to
differentiate between different types of damage and hints at the cause
of residual damage, especially when multiple statuses and field
conditions are in play.
Yellow coloration for convert healing damage

This color was difficult to perfect.  Too yellow and it looks like
Lightning damage, too green and it can be confused with actual healing.