Split backend service into checker and generator

Both are linked through a unix socket.

backend/locked.go

@@ -1,30 +0,0 @@
-package main
-
-import (
-	"encoding/json"
-	"log"
-	"os"
-
-	"srs.epita.fr/fic-server/libfic"
-)
-
-var TeamLockedExercices = map[int64]map[string]bool{}
-
-func treatLocked(pathname string, team *fic.Team) {
-	fd, err := os.Open(pathname)
-	if err != nil {
-		log.Printf("[ERR] Unable to open %q: %s", pathname, err)
-		return
-	}
-
-	var locked map[string]bool
-
-	jdec := json.NewDecoder(fd)
-	if err := jdec.Decode(&locked); err != nil {
-		log.Printf("[ERR] Unable to parse JSON %q: %s", pathname, err)
-		return
-	}
-
-	TeamLockedExercices[team.Id] = locked
-	log.Printf("Team %q (tid=%d) has locked %d exercices", team.Name, team.Id, len(locked))
-}