support for escapeinside of pygments 2.0

Pygments 2.0 supports escapeinside to add formatted text inside minted.

This allows to mark code disabilng verbatim using the provided mark sign.
\begin{minted}[escapeinside=||]{python}
def parse(line):
    if not line.|\colorbox{yellow}{startswith}|(('foo','bar')):
        continue
    ...
\end{minted}