(closes#2633)
* move osmChangeJXON from osm service to osmChangeset
* cleanup putChangeset for code clarity
* adjust params for callbacks (pass changeset around instead of changeset_id)
* add commit.reset() to reset changeset object after successful save
* improve checks for changeset tags (trim whitespace, etc)
(see #3777)
* When entering Save mode, map content transitions inactive: appears grayscale
and dims slightly so colorblind users perceive a change. The sidebar controls
still let the user review their edits, or return to editing to address any
warnings.
* Adjusted the language a little bit "Save" -> "Upload" to make it clear that
an Upload needs to happen. No more 2 Save buttons.
