BUGFIX: better error message when loading of dynamic lib proc fails

tests/tsplit.nim

@@ -0,0 +1,14 @@
+import strutils
+
+var s = ""
+for w in split("|abc|xy|z", {'|'}):
+  s.add("#")
+  s.add(w)
+
+if s == "#abc#xy#z":
+  echo "true"
+else:
+  echo "false"
+  
+#OUT true
+

tests/ttuple1.nim

@@ -0,0 +1,16 @@
+const romanNumbers = [
+    ("M", 1000), ("D", 500), ("C", 100),
+    ("L", 50), ("X", 10), ("V", 5), ("I", 1) ]
+
+var c = 0
+for key, val in items(romanNumbers):
+  inc(c)
+  stdout.write(key & "=" & $val)
+  if c < romanNumbers.len: stdout.write(", ") else: echo""
+#echo""
+
+proc PrintBiTuple(t: tuple[k: string, v: int]): int =
+  stdout.write(t.k & "=" & $t.v & ", ")
+  return 0
+  
+