Support for more panes

[wl-stepp]

Thank you for the great plugin!

I am using fman with four panes by setting them in the Sessions.json and wanted to use the favorites feature. So I made some small changes to the code to allow for more panes to be stored:
When setting the favorite pair

for i in range(len(panes)):
    dirName = shortenDirPath(panes[i].get_path())
    favEntry = favEntry + "|" + dirName 

When retrieving it:

favName, *favPaths = dirTuple.strip().split('|')
if favName == dirName:
    i = 0
    for fav in favPaths:
        if '://' in fav:
            newPath = expandDirPath(fav)
            panes[i].set_path(newPath)
        else:
            newPath = as_url(expandDirPath(fav))
            panes[i].set_path(newPath)
        i = i + 1

In case you want to consider implementing this.