Add import support for ssl certificate, http/s proxy and url map (hashicorp#678)

Author: krotkiewicz

docs/r/compute_ssl_certificate.html.markdown

@@ -90,3 +90,11 @@ exported:
 
 [1]: /docs/providers/google/r/compute_target_https_proxy.html
 [2]: /docs/configuration/resources.html#lifecycle
+
+## Import
+
+SSL certificate can be imported using the `name`, e.g.
+
+```
+$ terraform import compute_ssl_certificate.html.foobar foobar
+```

docs/r/compute_target_http_proxy.html.markdown

@@ -89,3 +89,11 @@ exported:
 * `proxy_id` - A unique ID assigned by GCE.
 
 * `self_link` - The URI of the created resource.
+
+## Import
+
+Target HTTP Proxy can be imported using the `name`, e.g.
+
+```
+$ terraform import compute_target_http_proxy.foobar foobar
+```

docs/r/compute_target_https_proxy.html.markdown

@@ -99,3 +99,11 @@ exported:
 * `proxy_id` - A unique ID assigned by GCE.
 
 * `self_link` - The URI of the created resource.
+
+## Import
+
+Target HTTPS Proxy can be imported using the `name`, e.g.
+
+```
+$ terraform import compute_target_https_proxy.foobar foobar
+```

docs/r/compute_url_map.html.markdown

@@ -160,3 +160,14 @@ exported:
 * `map_id` - The GCE assigned ID of the resource.
 
 * `self_link` - The URI of the created resource.
+
+## Import
+
+URL Map can be imported using the `name`, e.g.
+
+```
+$ terraform import google_compute_url_map.html.foobar foobar
+```
+
+
+Currently `host_rule`, `path_matcher` and `test` importing is not yet supported.