Additional Options for outline environment

[P4ntomime]

Idea

• Add parameter similar to tabular to specify outline level type

% possible levels: e, i, d (enumerate, itemize, description respectively)
\begin{outline}{e i i e}
  \1 This will be enumerated
    \2 This will be itemized
      \3 This will also be itemized
        \4 This will be enumerated again   
\end{outline}

• Add optional parameters to given parameters to style levels

% possible levels: e, i, d (enumerate, itemize, description respectively)
\begin{outline}{e i e{label=\alph*.}}
  \1 This will be enumerated
    \2 This will be itemized
      \3 This will be alph-enumerated 
\end{outline}