Add download control for all events to Log view.

The log until now offered a download control only in sequence
view mode. With this change, download is available (albeit not
in all formats) for the entire log.

To download events for a selection of dates (constrained by day,
week or month) the user should use the Calendar view instead.

lib/www/client/source/src/views/Log.vue

@@ -86,6 +86,49 @@
               >PDF</v-list-item>
             </v-list>
           </v-menu>
+          <v-menu v-else>
+            <template v-slot:activator="{on, attrs}">
+              <v-btn class="ml-5" small v-on="on" v-bind="attrs">
+                <span class="d-none d-lg-inline">Download as…</span>
+                <v-icon right small>mdi-cloud-download</v-icon>
+              </v-btn>
+            </template>
+
+            <v-list>
+              <v-list-item
+                :href="`/api/project/${$route.params.project}/event?mime=application%2Fvnd.seis%2Bjson&filename=event-log-multiseis.json`"
+                title="Download as a Multiseis-compatible Seis+JSON file."
+              >Seis+JSON</v-list-item>
+              <!-- Not yet implemented
+              <v-list-item
+                :href="`/api/project/${$route.params.project}/event?mime=application%2Fgeo%2Bjson&filename=event-log.geojson`"
+                title="Download as a QGIS-compatible GeoJSON file"
+              >GeoJSON</v-list-item>
+              -->
+              <v-list-item
+                :href="`/api/project/${$route.params.project}/event?mime=application%2Fjson&filename=event-log.json`"
+                title="Download as a generic JSON file"
+              >JSON</v-list-item>
+              <v-list-item
+                :href="`/api/project/${$route.params.project}/event?mime=application%2Fyaml&filename=event-log.yaml`"
+                title="Download as a YAML file"
+              >YAML</v-list-item>
+              <v-list-item
+                :href="`/api/project/${$route.params.project}/event?mime=text%2Fcsv&sortBy=tstamp&sortDesc=false&filename=event-log.csv`"
+                title="Download as Comma Separated Values file"
+              >CSV</v-list-item>
+              <!-- Not yet implemented
+              <v-list-item
+                :href="`/api/project/${$route.params.project}/event?mime=text%2Fhtml&filename=event-log.html`"
+                title="Download as an HTML formatted file"
+              >HTML</v-list-item>
+              <v-list-item
+                :href="`/api/project/${$route.params.project}/event?mime=application%2Fpdf&filename=event-log.pdf`"
+                title="Download as a Portable Document File"
+              >PDF</v-list-item>
+              -->
+            </v-list>
+          </v-menu>
 
           <v-spacer></v-spacer>
           <v-text-field