When a diff contains a line starting with '--- ', diff2html.py
misinterprets it as being the header of a diff for a different file,
which apparently causes it to hang. This fix tries to work around the
problem by being a bit more selective about the format of the headers

It happened quite frequently to me that the paper stopped compiling
after the removal of the \usepackage{hyperref} from the main tex file.
Maybe it's just save to let it in.

This comes at the cost that we should not access the global sys.argv in
other functions. Hence, the get_paper_from_args_or_pwd() now can not
parse the episciences id from the args anymore.

Add command to compile paper on arXiv, and compare to local version.

See merge request !1

For instance, the log literally contains the string

    .95 \U/Mn

which leads to a decoding error. Instead, lets just read it with the
default encoding. Additionally, let us 'ignore' encoding errors in the
log.