Renamed collector, aggregator to api server, api folder to agent (#133)

* Renamed aggregator -> apiServer.

* Format errors with container names.

* Renamed collector -> apiServer.

* Rephrased help messages.

* Moved api -> agent.

* Continue renameing api -> agent in Makefile and Dockerfiles.

agent/pkg/utils/pathUtils.go

@@ -0,0 +1,50 @@
+package utils
+
+import (
+	"github.com/djherbis/atime"
+	"os"
+)
+
+type ByModTime []os.FileInfo
+
+func (fis ByModTime) Len() int {
+	return len(fis)
+}
+
+func (fis ByModTime) Swap(i, j int) {
+	fis[i], fis[j] = fis[j], fis[i]
+}
+
+func (fis ByModTime) Less(i, j int) bool {
+	return fis[i].ModTime().Before(fis[j].ModTime())
+}
+
+
+type ByName []os.FileInfo
+
+func (fis ByName) Len() int {
+	return len(fis)
+}
+
+func (fis ByName) Swap(i, j int) {
+	fis[i], fis[j] = fis[j], fis[i]
+}
+
+func (fis ByName) Less(i, j int) bool {
+	return fis[i].Name() < fis[j].Name()
+}
+
+
+type ByCreationTime []os.FileInfo
+
+func (fis ByCreationTime) Len() int {
+	return len(fis)
+}
+
+func (fis ByCreationTime) Swap(i, j int) {
+	fis[i], fis[j] = fis[j], fis[i]
+}
+
+func (fis ByCreationTime) Less(i, j int) bool {
+	return atime.Get(fis[i]).Unix() < atime.Get(fis[j]).Unix()
+}