[CLEANUP] Update gitignore file

Author: Antoine Morvan

.gitignore

@@ -40,9 +40,8 @@ Thumbs.db
 #######################################
 bin/
 target/
-xtend-gen/
+**/xtend-gen/
 lib/
-/plugins/org.ietr.preesm.codegen.xtend/xtend-gen/
 *~
 *._trace
 *.orig
@@ -55,6 +54,7 @@ DAG/*.graphml
 stats/xml/
 stats/mat/algo/
 stats/mat/archi/
+**/org.ietr.preesm.memory.temporary/**
 
 # Eclipse files #
 #################