解决出现0==i或者0===i的类似判定时候，提取变量bug

[uc2dabing]

如果模板出现类似if(0==i)或者if(0===i)的时候，提取变量bug，会把0也作为变量提取出来。
debug代码如下：
var $helpers=this,0=$data.0,i=$data.i,

[aui]

变量静态分析的算法已经更新

// 静态分析模板变量
var KEYWORDS =
    // 关键字
    'break,case,catch,continue,debugger,default,delete,do,else,false'
    + ',finally,for,function,if,in,instanceof,new,null,return,switch,this'
    + ',throw,true,try,typeof,var,void,while,with'

    // 保留字
    + ',abstract,boolean,byte,char,class,const,double,enum,export,extends'
    + ',final,float,goto,implements,import,int,interface,long,native'
    + ',package,private,protected,public,short,static,super,synchronized'
    + ',throws,transient,volatile'

    // ECMA 5 - use strict
    + ',arguments,let,yield'

    + ',undefined';
var REMOVE_RE = /\/\*(?:.|\n)*?\*\/|\/\/[^\n]*\n|\/\/[^\n]*$|'[^']*'|"[^"]*"|[\s\t\n]*\.[\s\t\n]*[$\w\.]+/g;
var SPLIT_RE = /[^\w$]+/g;
var KEYWORDS_RE = new RegExp(["\\b" + KEYWORDS.replace(/,/g, '\\b|\\b') + "\\b"].join('|'), 'g');
var NUMBER_RE = /\b\d[^,]*/g;
var BOUNDARY_RE = /^,+|,+$/g;
var getVariable = function (code) {

    code = code
    .replace(REMOVE_RE, '')
    .replace(SPLIT_RE, ',')
    .replace(KEYWORDS_RE, '')
    .replace(NUMBER_RE, '')
    .replace(BOUNDARY_RE, '');

    code = code ? code.split(/,+/) : [];

    return code;
};