#5 evaluate orders at every key-stroke

[Guy Tsafnat]

the client order validator should parse all the orders
at every keystroke.
All error messages generated by the parser should be
categorized as report-as-typed or report-after-
completion only.
whether an order is complete or not should be
determined by the location of the cursor and the line
itself.

The arrow redrawing should be updated only when an
order was changes, added or deleted, not on every key-
stroke.