Implement most of the spec reusing scribe & nefthera code

ocaml/lib/system/file.ml

@@ -0,0 +1,14 @@
+let read_channel channel =
+    let buffer = Buffer.create 4096 in
+    let rec read () =
+        let line = input_line channel in
+        Buffer.add_string buffer line;
+        Buffer.add_char buffer '\n';
+        read ()
+    in
+    try read () with
+        End_of_file -> Buffer.contents buffer
+
+let read path =
+    let channel = open_in path in
+    read_channel channel