template.go 的urlfor Func注释有误

增加编译模版函数BuildTemplate可变参数，使之支持单个或多个模版的编译，同时针对开发模式，每个请求只编译当前请求相关模版，不再每次请求都编译全部模版

added tests config/json_test that test missing key usecases. created a template function to fetch AppConfig values

add api comments in file memzipfile.go,reload.go,router.go,template.go and templatefunc.go, fix spelling error GetInitListner as GetInitListener.

Adding assets_js, assets_css template functions

We can specify "TemplateLeft" and "TemplateRight" but they did not work as these two changes are required.

UrlFor(endpoint string, values ...string) string

you can set the delimiter like this

beego.TemplateLeft="{#"
beego.TemplateRight="#}"

or can set the config file like app.ini

templateleft={#
templateright=#}