Hide Maven view by default

[chambery]

Maven Projects view should hide if the project isn't Maven-enabled. I added when to the package.json :

		"views": {
			"explorer": [
				{
					"id": "mavenProjects",
					"name": "Maven Projects",
					"when": "workspaceContains:pom.xml"
				}

which succeeds in hiding when I don't have a Maven project, but doesn't show in the view contributions list when I load my Java project containing a pom.xml.

[Eskibear]

As far as I know, workspaceContains:${toplevelfilename} is a kind of ActivationEvents, not supposed to be used in when conditional.

Ref:
https://code.visualstudio.com/docs/extensionAPI/activation-events#_activationeventsworkspacecontains

About hiding the view by default, there's a related issue #36 . And since there's new APIs in v1.23, we're considering whether to put it into a separate view for better experience.

[Eskibear]

can be done by Context value, value is set by command.setContext API

[Eskibear]

fixed in #80