[command] allow to call symfony command from anywhere

[connorhu]

closes #204

What this cause?
a) cwd is set properly => nothing
b) cwd is not set properly => somewhere something cause error

But it's the caller's responsibility to make sure cwd is set properly.
The symfony command sets cwd anyway:

symfony1/lib/task/generator/skeleton/project/symfony

Line 12 in 0c9ba11

chdir(__DIR__);

[alquerci]

LGTM, but a BC break concern.

About checkProjectExists()

As a public method, we do not know the usage of this public method.
Changing its behaviour is a BC break.

Only removing its usage, will be enough.

I suggest keeping it untouched OR use config/ProjectConfiguration.class.php like

symfony1/data/bin/symfony

Lines 12 to 15 in 573d579

	// project exists?
	if (file_exists('config/ProjectConfiguration.class.php'))
	{
	require_once('config/ProjectConfiguration.class.php');

[connorhu]

This feature protects the developer during development from doing the inappropriate thing (e.g. calling cli.php in the wrong way). But on a complete system, this method is no longer relevant and as I wrote, the cwd is handled by the symfony script. There are already tools used during development which are not tested and do not work properly under certain circumstances (e.g. #341).