Add a check for redundant . and e in number parser

[vearutop]

This PR naively fixes false positive parsing of an invalid number that contains more than one . or e.
#88 (comment)

package main

import (
	"fmt"

	"github.com/valyala/fastjson"
)

func main() {
	v, err := fastjson.ParseBytes([]byte(`[127.0.0.1]`))
	if err != nil {
		fmt.Println("failed:", err.Error())
	} else {
		fmt.Println("passed:", v.Type())
	}

	err = fastjson.ValidateBytes([]byte(`[127.0.0.1]`))
	if err != nil {
		fmt.Println("validation failed:", err.Error())
	}

	// Output:
	// passed: array
	// validation failed: cannot parse JSON: cannot parse array: missing ',' after array value; unparsed tail: ".0.1]"
}