NewFromString should accept unicode minus sign

[tzachshabtay]

The unicode minus sign U+2212 is not supported in NewFromString, only the ascii minus sign is.

Example

[mwoss]

Thanks for reporting this problem :3! I will create a task for that in our backlog and try to fix it in the 1.5 release (probably I won't be able to include this fix in 1.4)