Subreddit network management tools

[amici-ursi]

Every mod action that gets done in one subreddit also needs to be propagable to the entire network of subreddits. Some of these actions are:

• [x] AutoModerator #29
• [ ] subreddit/about/edit settings
• [ ] subreddit/about/flair settings
• [ ] sticky posts
• [ ] sidebars
• [ ] bans
• [x] mods
• [x] toolbox configs (/wiki/toolbox json) (amici has ideas for not breaking sub-specific settings)
• [ ] CSS (including image uploads) #43
• [x] send modmail to each subreddit
• [ ] about/rules #42

Where appropriate, we need to account for Network content and Subreddit content by using "start blah end" delimiters (for example, the sidebar and automoderator).

Let's use this issue to finalize the ideas we have on Discord.

[scowcron]

some of these make sense to group into one command, some don't. I'm thinking a general purpose ion_propagate, with separate commands for ion_invite_mods and ion_bulkmail right now.

[scowcron]

16 is no longer valid, this will replace it.