SF Bugs#106: Fix incorrect location on opening .vik file saved in different locale.

SF Bugs#106: Fix incorrect location on opening .vik file saved in different locale.

Enable reading in of decimal values that may contain either '.' or ',' as the separator.
Need to use modified version of strtod() since the standard C library does not support reading in values from a different locale.

Ideally Viking shouldn't have saved these values into the file in a locale dependent manner,
but for a few values this is the case (ever since the first public release of Viking).
Thus to maintain backwards compatibility need to handle standard variations of the decimal separator.

Selected strtod() from the Sanos project for it's simplicity
(compared to 'David M. Gay' version: http://www.netlib.org/fp/dtoa.c - which may handle extremes of precision better - but such values aren't encountered in Viking)