move property::connect to model::connect.
update docs.
fix documentation.
add experimental mixin classes for property::link_base and property::link.
rename file
rename file
Merge branch 'descriptor_mixins'
add semantics to property::link::decompose_numeric_timeseries (only when specialized with history_property_wrapper).
add property::print_decomposed.
add some testing code in position_attitude_ribbon_geometry.cpp.