MINOR: tests: First regression testing file.

Add a makefile target 'reg-tests' to run all regression testing file
found in 'reg-tests' directory.
Add reg-tests/lua/h00000.vtc first regression testing file for a LUA
fixed by f874a83 commit.
diff --git a/.gitignore b/.gitignore
index 73eaeae..32a8a84 100644
--- a/.gitignore
+++ b/.gitignore
@@ -22,6 +22,7 @@
 !/tests
 !/debian
 !/scripts
+!/reg-tests
 # Reject some generic files
 *.o
 *~