Added class OrderedMap which is insert-order preserving map.
Using OrderedMap to hold wells in Schedule object - thereby preserving
well insert order.
Merge pull request #206 from joakim-hove/wellspecs-ordered-wells

Wellspecs ordered wells
fixed: initialize members
changed: don't use parameter names that conflicts with member function names

quells warnings (with gcc 4.8)
fixed: mark static symbols as such to quell warnings
fixed: remove misplaced semi-colons
fixed: don't check for unsigned values being positive

they definitely are. quells warnings