Support for cygwin command "cygstart"

[skyegecko]

Hi,

I primarily use vim under cygwin, and would like to use vim-shell and vim-misc to open URLs in my default browser. Cygwin provides an all-purpose command called cygstart which opens a given file or URL using the default associated program in Windows.

I've modified autoload/xolox/misc/open.vim to use cygstart by adding it to the list of command line browsers, but I'm sure a neater (and possibly configurable) method of incorporating this feature is possible. Is this something you would consider including?