start of tests refactoring; sqlite3 new wrapper fixes

tests/accept/compile/twalker.nim

@@ -0,0 +1,13 @@
+# iterate over all files with a given filter:
+
+import
+  os, times
+
+proc main(filter: string) =
+  for filename in walkFiles(filter):
+    writeln(stdout, filename)
+
+  for key, val in iterOverEnvironment():
+    writeln(stdout, key & '=' & val)
+
+main("*.nim")