ReaderWriterLock implementation, solves threading issues

0.7.1 Release notes:

• This is a debug one shortly released to solves threading issue in 0.7.0.

0.7.0 Release notes:

• new mouse move handling, improve perf, introduce new recursive method in GraphicObject 'PointIsIn (ref Point p)'
• new TemplatedGroup architecture: in hierarchical group, TemplatedGroup are no longer required on each node, only a container with 'ItemsContainer' should be provided in ItemTemplates with sub data fetching.
• Delete and Remove widget differentiation in group.
• Drag and Drop basics implemented, not fully tested.
• binding address starting with '/' start search at current node, not in template.
• Fit measure units changed from Pixel to Percent.
• prevent mouse evt on label not selectable.
• crowIDE wip, need CrowEdit reference (available on GitHub).
• CheckBox reused as base in several template which need 2 states inherited from it.
• FocusParent internal variable, allow easyer popup parenting while keeping logical parenting usefull for other things.
• InstantiatorException with file name.
• load all assemblies in bin dir at startup to allow usage of several Widget assemblies.
• Context menu basic mechanic, may be improved.
• ObservableList that could be used as data source for TempletedGroups.
• Configuration no longer static to allow multiple config files handling in single application.
• styling is no longer static in iface to allow different styling context between ifaces.