fix bug 1243827

fix bug 1243827

If the text of a scalar node of the parsed tree starts with a digit
or '+' or '-', the function resolve() removes all '_' from it and
tries to convert the new string into a float or integer. When this
fails, the variant without the '_' was returned as a string value,
which is obviously wrong.

I also removed the loop where strings.Replace(in, "_", "", -1) was
called with a with a simple of Replace(). This should have the same
result but looks a bit simpler.

https://code.launchpad.net/~adeuring/goyaml/1243827/+merge/211015

(do not edit description out of merge proposal)

[abel.deuring, 2014-03-14 10:25:53]

Please take a look.