Translations:Sketcher project/14/en

For 0.13:
 * 1) support for arc/arc and arc/circle in the tangent constraint - DONE [logari81]
 * 2) support for arcs in the perpendicular constraint - DONE [logari81]
 * 3) zoom-independent arrows (symmetry constraint) / dimension lines - DONE [mrlukeparry]
 * 4) external geometry / constraints -  DONE [logari81]
 * 5) box selection -  DONE [mrlukeparry]
 * 6) mouse dragging of multiple selection - SKIPPED for 0.14
 * 7) better constrainess diagnostics (Issue #691)- DONE [logari81]
 * 8) list of Geometries in the task panel (similar to the list of Constraints) - SKIPPED for 0.14
 * 9) support for points as construction geometry - DONE [logari81]
 * 10) add a popup menu option to convert a coincident points constraint to tangency constraints - SKIPPED for 0.14
 * 11) make symmetry constraint to work with symmetry points instead of symmetry lines (useful e.g. for midpoint definition) - DONE [logari81]