GRDECL format reader update
Replaced algorithm in GRDECL reader that determines location of intersection of segments from projected to physical coordinates. Privously it was performed with bilinear interpolation of pillar coordinates. This leads to segments being curvilinear arcs in physical world. Now the location is determined at the middle of the shortest possible segment between two original segments. ECL_CURVILINEAR option is absolute. GRDECL reader now parses wells, well complitions, well specifications, well groups and defines well schedule through tags.