Changeset 758:28cfac049a6a in lemon for doc

Unify member names in heaps (#299)

The following renamings are made.

Public members:

• UnderFlowPriorityError? -> PriorityUnderflowError? ("underflow" is only one word)

Private members:

• bubble_up() -> bubbleUp()
• bubble_down() -> bubbleDown()
• second_child() -> secondChild()
• makeroot() -> makeRoot()
• relocate_last() -> relocateLast()
• data -> _data
• boxes -> _boxes