bug 380584: [api] provide an api for lazy fetching of changes in
ChangeSet

implemented ChangeSetIterator, which converts the changesets on demand.
removed the lazy changes list, as it did not work due to the list copy
in the changeset constructor, added a the lazy changeset class instead,
which loads the changes lazily on access.

https://bugs.eclipse.org/bugs/show_bug.cgi?id=380584

Change-Id: I0f21f97f217611f34ea374d3f9aeb92fc769f336
5 files changed