Added regex support as per issue #164.

jq now depends on oniguruma for regex support.
Modified configure.ac accordingly.

Added valgrind suppression file for oniguruma to prevent one-time and bounded
leaks from causing tests to fail.

Signed-off-by: Nicolas Williams <nico@cryptonector.com>

tests/onig.supp

@@ -0,0 +1,21 @@
+{
+	onig node recycling
+	Memcheck:Leak
+	...
+	fun:onig_parse_make_tree
+	...
+}
+{
+	onig unicode case insensitivity 1
+	Memcheck:Leak
+	...
+	fun:setup_tree
+	...
+}
+{
+	onig unicode case insensitivity 2
+	Memcheck:Leak
+	...
+	fun:onig*unicode*
+	...
+}