2014-01-08
* version 1.1.2 to 1.1.3
* dag.sim

2012-11-04
* version 1.1.1 to 1.1.2
* dag.draw
- new option to allow NOT drawing the X->Y arc, or drawing it w/out "?"
* changes to multiple functions to allow custom node symbols
- no special formatting has been programmed, i.e. the string length is ignored
- affected functions: dag.draw, dag.init, dag.legend, dag.letter, write.paths, summary_dagRdag
* dag.letter
- added note on adjustment marking by bar/underline (not for unknowns) in docu.
* new function: demo.dag7
- same as demo.dag3, but with alternative node symbols

2010-06-14
* version 1.0.1 to 1.1.1
* removed empty sections from .Rd files
* dag.init
- now adds version of dagR to the DAG
- now assigns class "dagRdag" 
- elaborated documentation regarding node numbering
* rm.node, add.arc, rm.arc
- now also remove searchType and searchRes
* dag.adjust
- if adjustment set not empty, now also removes searchType and searchRes
- elaborated documentation regarding node numbering
* is.acyclic
- new argument: maxSecs
* new function: viv
* new function: msas
* new function: dag.search
* new function: summary_dagRdag

OPEN ISSUES
* brute.search
- has trouble if there are no eligible adjustment sets to evaluate
  (e.g. only unknown variables, but allow.unknowns=FALSE)
* dag.draw
- for some reason, this sometimes has a problem because components
  of dag$arc strangely become lists instead of numeric
* dag.letter
- unknowns are not shown with adjustment marking
* summary_dagRdag should become summary.dagRdag...
* helper functions should go internal...
