inner input width to 100% if calculation is NaN

Some usecases pre-render widget before attaching to DOM. In these cases inner input width calculation yields NaN because jquery's dimension methods yields NaN. For these cases default the width to 100% instead of minWidth. This implementation also has the benefit of setting width only once instead of twice in the previous impl.
Merge pull request #136 from taivo/master

inner input width to 100% if calculation is NaN