implemetation of AtomCommandline to preserve args

[deepak1556]

Inital work for #1248 . @zcbenz If its desirable to have our own commandline class , then i can implement other methods from base::commandline for our needs and eliminate its usage. If this is too heavy for a trivial stuff, feel free to close it. would love to hear any better approaches :)

EDIT: sorry didnt mean eliminate base::commandLine but just atomCommandLine will wrap around it, so all commandLine calls to base will happen through this new class.

[bwin]

Thanks for working on this.

[zcbenz]

We don't need to replicate base::CommandLine's interface, our purpose is to keep a copy of argv and then pass it to node::CreateEnvironment, so a simple singleton class that keeps a references to argv should be enough in our case.

[deepak1556]

@zcbenz then this hack would be present to stitch atom-shell swtich arguments from https://github.com/atom/atom-shell/blob/master/atom/app/atom_main_delegate.cc#L71 before sending to node::Environment ?

[zcbenz]

Since we will use the original argv, this hack will not be needed anymore.

[zcbenz]

We can make AtomCommandLine's data members static so we don't have to create a current_process_commandline_ instance.

[deepak1556]

@zcbenz made the changes and added tests, havnt tested on windows though. Would be nice if someone did :)

[zcbenz]

It works on Windows, thanks!