remove atari need to use browser internal data structures
Use API to get current scale.
Use API to get content for view source.
Use browser_window_stop_available()

Looking at bw->loading_content was bad and wrong in the cases
of frames, and object fetches.
Shouldn't need browser_private.h now.
fix missing semicolon
Use browser_window_can_select(), instead of assuming based on content type.
Use browser_window_get_url() instead of getting URL from current content.
Use API for getting browser window history.
Use browser_window_get_content() to get the current content.

Although I dislike this API, and it may go at some point.
Should be free of reliance on browser window internals here now.
Should be a while loop in case of multiple simultaneous event triggers.
Use browser_window_get_content where we need to.
Use API to get URL.
Simplify ami_history_open API and use correct call to get history object.
Use API to find if content is selectable, instead of guessing.
Shouldn't need browser_private.h now.
Fix brackets.
Revert "Should be a while loop in case of multiple simultaneous event triggers."

This reverts commit 9dcf001a0bf6d09864783125390e20c8eb53c12f.

For ehatever reason this is entirely broken, but I'm in the process of rewriting so just revert for now to get the working builds again.
Initial steps for a scheduler process