src: browser.js: fix partialOutputMode support for Internet Explorers, also reorganize so that 'current' and 'partial' have consistent information in each 'downloading' callback
src: browser.js: fix partialOutputMode support for Internet Explorers, also reorganize so that 'current' and 'partial' have consistent information in each 'downloading' callback

jakutis/httpinvoke,jakutis/httpinvoke,npmcomponent/jakutis-httpinvoke,fuzeman/httpinvoke,fuzeman/httpinvoke