Sandro Santilli e8b7b82bbb Implement scientific notation for double-to-string
Also fixes tests for 1e5 expecting fixed precision rather than
scientific notation (stringstream gives scientific notation indeed)

The only still failing test now is the one having less than 16
significant digits of precision, due to the boost bug:
https://svn.boost.org/trac/boost/ticket/7785
2012-12-17 19:29:44 +01:00
..