Add initial JSON formatter

It works and can format all "plain" Perl data, but has a few known bugs
and limitations that still need to be worked out.

It's about 8x smaller than JSON::XS's encoder and *much* smaller than
Cpanel::JSON::XS, but this is just a first attempt, it'll grow.

Makefile.PL

@@ -8,4 +8,6 @@ WriteMakefile(
     META_MERGE => {
         dynamic_config => 0,
     },
+    OPTIMIZE => '-g -O2 -Wall -Wextra',
+    depend => { '$(OBJECT)', 'c/*.c' },
 );