errorbar()

Here is simple `errorbar` similar to matplotlib to wrap `ErrorBarsX/Y` and `SymmetricErrorBarsX/Y`. Syntax is like this; for symmetric errorbars:
```julia
errorbar(x,y,xerr=e,yerr=f, color="blue", linewidth=5.0)
```
and for non-symmetric:
```julia
errorbar(x, y, xerr=[e, f], yerr=[g, h],color="red")
```

Merge if you want or use as a frame if you want to make changes...