Squashed commit of the following:

commit b9877e37f7
Author: Surinna Curtis <ekiru.0@gmail.com>
Date:   Wed Jul 12 00:50:10 2017 -0500

    account for the eye in the chars left count for local-only toots

commit 56ebfa9654
Author: Surinna Curtis <ekiru.0@gmail.com>
Date:   Wed Jul 12 00:21:02 2017 -0500

    factor out an AdvancedOptionsToggle to avoid unnecessary re-renders

commit 04cec44ab8
Author: Surinna Curtis <ekiru.0@gmail.com>
Date:   Wed Jul 12 00:20:24 2017 -0500

    s/changeComposeAdvancedOption/toggleComposeAdvancedOption/g

commit af5815dee7
Author: Surinna Curtis <ekiru.0@gmail.com>
Date:   Tue Jul 11 23:55:19 2017 -0500

    clicking anywhere on the whole advanced option toggles