remove const variant of json_ptr; it never got used.  and hide it in impl ns
Simplify, sanitize, modernize, and fix bugs in json_cast<>() and make_json()
fix whitespace damage from restoration of std:: prefixes
use perfect forwarding in operator []
fix minor errors in json api: add erase(int), rename arr_clear -> aclear
Unify and simplify json iterator code
variadic json .get() and .set()
test variadic json accessors
Merge pull request #75 from chipdude/master

json renovation