Make gmp build, and run all the tests

This requires some custom rules, checking the config in, and m4.  Build
and run all the tests to confirm we got all the pieces.

Change-Id: I5b30c3b0031188dafe198a22fafbd3ad2240ce01
diff --git a/WORKSPACE b/WORKSPACE
index dced1f0..eb7ed28 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -66,6 +66,10 @@
     "//debian:gstreamer_armhf.bzl",
     gstreamer_armhf_debs = "files",
 )
+load(
+    "//debian:m4.bzl",
+    m4_debs = "files",
+)
 load("//debian:packages.bzl", "generate_repositories_for_debs")
 
 generate_repositories_for_debs(python_debs)
@@ -100,6 +104,8 @@
 
 generate_repositories_for_debs(gstreamer_armhf_debs)
 
+generate_repositories_for_debs(m4_debs)
+
 http_archive(
     name = "python_repo",
     build_file = "@//debian:python.BUILD",
@@ -740,3 +746,10 @@
     strip_prefix = "MarkupSafe-1.1.1",
     url = "http://www.frc971.org/Build-Dependencies/MarkupSafe-1.1.1.tar.gz",
 )
+
+http_archive(
+    name = "m4_v1.4.18",
+    build_file = "@//debian:m4.BUILD",
+    sha256 = "ee8dfe664ac8c1d066bab64f71bd076a021875581b3cc47dac4a14a475f50b15",
+    url = "http://www.frc971.org/Build-Dependencies/m4.tar.gz",
+)