make both gcc and clang happy with how cx_json_value_nothing is initialized

fix memory leak in case of json parser errors

use json reader state macros everywhere

fix incomplete json object not resulting in syntax error

fix memory leak in json reader when handling incomplete tokens

add test for parsing json with multiple incomplete tokens

simplify cx_json_value_nothing initialization

add first draft of json implementation - relates to #431

(0) -300 -100 -30 -10 -8 +8 +10 +30 +100 tip

mercurial