handle base64 download links in desktop mode
provide default file extension for base64 downloads
ensure maximized -> ensure height
Revert "ensure maximized -> ensure height"

This reverts commit 4fe12129998f1fd8aad9f47dad54121a10eb877e.
Revert "Revert "ensure maximized -> ensure height""

This reverts commit a676fde352e9740a682a5801c119fbe37eb25b76.
hookups for ensure height handler
explicit maximize method
implement ensure height event for panes
rename viewApp -> viewer
Merge remote-tracking branch: upstream/master