Integers as keys

[cjkjellander]

We discovered that by accident lejson worked on using integers as keys, but only if the integer what 0-255. This fixes so all integers can be used as keys and with a new option they can be decoded to the same map as before encoding.

New option integer_and_atom

  1) lejson_test:config_test_/0: integer_as_key
     Failure/Error: {error,badarg,
                        [{erlang,iolist_to_binary,
                             [["{",["\"",256,"\"",":",[<<"1">>]],"}"]],
                             []},
                         {lejson,encode,1,
                             [{file,
                                  "/home/cjk/git/campanja/lejson/src/lejson.erl"},
                              {line,32}]},
                         {lejson_test,test_opts,1,
                             [{file,
                                  "/home/cjk/git/campanja/lejson/test/lejson_test.erl"},
                              {line,123}]},
                         {eunit_test,run_testfun,1,
                             [{file,"eunit_test.erl"},{line,71}]},
                         {eunit_proc,run_test,1,
                             [{file,"eunit_proc.erl"},{line,510}]},
                         {eunit_proc,with_timeout,3,
                             [{file,"eunit_proc.erl"},{line,335}]},
                         {eunit_proc,handle_test,2,
                             [{file,"eunit_proc.erl"},{line,493}]},
                         {eunit_proc,tests_inorder,3,
                             [{file,"eunit_proc.erl"},{line,435}]}]}