Just because your browser CAN do those things doesn't mean it HAS to be able to do those things to be a web browser.
Anything program that is capable of rendering HTML and communicating with the http standard is a web browser, end of story.
The fact that modern browsers have the capabilities of ftp, javascript, flash, applets, ect. Doesn't make a program that does less, any less of a web browser.
Look at Lynx, It is a web browser that can't even render pngs or jpegs (ok, it has a gui... but its most commonly used without the gui) yet it is STILL a web browser.