adds spec for nested set attributes on issues
moves scoped nested set into own module, applies to WorkPackage
internal restructurings of nested_set patch
moves after save hooks to work_package
moves code into their own methods
alternate implementation of nested set with root id
renames parent to parent_issue_id for planning element - preliminary
removes reference to plugin from spec
reloads alternate_dates in specs where necessary
reorders and breaks up before filter
adapts form to use journal notes
adapts WorkPackage creation in cukes
removes parent_issue_id from scoped nested_set  as it is no longer necessary - yeah
replaces parent_issue_id with parent_id whereever it was to be found
removes redundant tests
adds documentation