Added variable direction (for arguments of functions). (But isn't thi…

…s info in

the function type already, at least now?)

Removed VARVAL, and added an optional Exp.Exp to VAR element

Added FUNCTION element

Added dump_debug (printing in paranthesized form) and dump_graphviz (use with
graphviz for drawing a graph).

Added relations get_matching_elements, find_element, get_output_vars etc.


git-svn-id: https://openmodelica.org/svn/OpenModelica/trunk@596 f25d12d1-65f4-0310-ae8a-bbce733d8d8e