Bug 1065306 - Part 1: s/suggestedsites-json/suggestedsites/. r=mshal

This is a mechanical change.  In future, we will probably want to
generate files not named like res/raw/file.json.  I'm not going to
handle res/not-raw right now; but I am going to handle not-file.json.
This smoothes that path.
Bug 1065306 - Part 2: Extract generated_file_template. r=mshal

This was essentially mechanical: s/$/$$/; s/suggestedsites/$(1)/; move
libs realchrome:: and GARBAGE rules into template.

I feel like there should be a more direct form of $$($(1)), but I can't
think of it.
Bug 1065306 - Part 3: Extract DotProperties helper. r=lucasr,mshal

The only substantive change here is to stop stripping the
'browser.suggestedsites.' prefix from each line when reading
region.properties.
Bug 1065306 - Part 4: Write localized res/raw-*/browsersearch.json. r=mshal