[Vala] Main

[pancake <pancake youterm com>]

We are going to add a new flag to gtkaml --main which automatically generates a main, constructs the first 
class passed and depending on a profile runs a specific code (gtk.init..)

I wonder if someone have ever used the --main flag in valac and if so, give some examples where it is useful.

Else i would prefer to remove it. Not because it collides with the above description, but because i cant find 
any serious use of the flag.

--pancake