cell support (Matlab/IdleX): python-shell-send-cell

[twmr]

I would like to see the function python-shell-send-cell implemented, which sends the active cell (delimited by ## like in idlex](http://idlex.sourceforge.net/features.html) ) to the python shell. Please also add a new face for the cell delimiter line (starting with ##).

see

[fgallina]

This is duplicated of #82

[twmr]

#82 is not really a duplicate of this feature request, it's its implementation ;)

[fgallina]

I know, they are so related that it can be considered as one, I tend to mantain the list of issues as clean as possible so that's why I pretty much marked this as duplicated.

Next time if you have some code to add try adding it to the ticket itself, less open tickets for each subject helps me to keep track of things better.

I'll continue the discussion on this on #82.

Thanks!