gluon-alfred: add fields idletime, memory and processes to statistics

package/gluon-alfred/files/lib/gluon/alfred/announce.d/statistics/idletime

+return tonumber(util.trim(util.exec("cut -d' ' -f2 /proc/uptime")))

package/gluon-alfred/files/lib/gluon/alfred/announce.d/statistics/memory

+local data = fs.readfile('/proc/meminfo')
+
+local fields = {}
+for k, v in data:gmatch('([^\n:]+):%s*(%d+) kB') do
+	fields[k] = tonumber(v)
+end
+
+return {
+	total = fields.MemTotal,
+	free = fields.MemFree,
+	buffers = fields.Buffers,
+	cached = fields.Cached,
+}

package/gluon-alfred/files/lib/gluon/alfred/announce.d/statistics/processes

+local running, total = fs.readfile('/proc/loadavg'):match('^[^ ]+ [^ ]+ [^ ]+ (%d+)/(%d+)')
+
+return { running = tonumber(running), total = tonumber(total) }