make loc_prev in trees optional - fixes #433

update CHANGELOG

add possibility to remove arrays of data and retrieve removed data

add cxTreeSetParent()

add functions to start iteration in a subtree

add missing details for 100% test coverage in tree.c

add test for creating an iterator over an empty tree

(0) -300 -100 -30 -10 -7 +7 +10 +30 +100 tip

mercurial