Core frames progress

I've done a first pass at core iframes in r12474. They should just work, without front end maintainers needing to do anything special. Here's an example page: http://www.netsurf-browser.org/temp/iframe/test-target.html The main things to be aware of are: a. They currently lack scrollbars b. Text selection with iframes is a bit funny c. Dragging box scrollbars inside iframes might not work d. The core form select widget isn't redrawn in iframes e. Pasting into form text inputs & textareas doesn't work in iframes. a: Before I give iframes scrollbars I need to do some stuff with CSS overflow scrollbars. b: Text selection is odd because of the current_redraw_browser hack that needs to be removed. Selection may also need some more work to handle browser windows not having their own gui window too. Fixing the other three things should be easy once I get round to them. Layout positioning of iframe boxes is actually improved now, since we no longer hard code them to inline-block box types. My plan is to fix all but 'b' before moving on to frame(set)s, unless anyone dislikes the way core (i)frames are being implemented. Maybe I'll do 'b' first too, it depends on when I, or someone else has a good idea. If anyone sees any issues not listed above let me know. Also, if you have any real-world examples of sites with (i)frame(set)s, please send me the URLs. -- Michael Drake (tlsa) http://www.netsurf-browser.org/