revise validate-extension-inputs.js to detect problems with percent i…

[benjiwheeler]

Resolves #137

Changes

• Adds functionality to the validate-extension-inputs.js script so it can check for the presence of the correct inputs of the form "/%d+/".
• makes validate-extension-inputs.js take a commandline arg to set which directory to use as input
• adds validate-extension-inputs.js to the tests run on editor/blocks translations

[chrisgarrity]

This is really helpful. One simple change is to replace all the console.log with process.stdout.write. I think it's a bit clearer for command line scripts. I wouldn't use process.stderr because it isn't an error in the script itself.

Also, would it make sense to rename the script 'validate-inputs.js' as it's not just for extensions any more.

[chrisgarrity]

Suggested change

	console.error(err.message + '\n'); // eslint-disable-line no-console
	process.stdout.write(err.message + '\n');

It's better to use process.stdout for this type of script (also doesn't trigger eslint)

[benjiwheeler]

@chrisgarrity, we're assigning this to you to decide what to do with this one! Hope it's helpful!