[otfstemhist] -h reports unrelated options, wrong tool name

[frankrolf]

[otfstemhist] -h reports unrelated options, wrong tool name

[skef]

When a glyph path has overlap one will typically need to process the path to remove it before one can get accurate stem information from it. Otherwise the independent outlines will appear as "pseudo-stems" to the processor. There isn't much difference between the stemhist case and the autohint case when it comes to overlap -- that's why those arguments are available in both cases.