Ref: #12

Fixes #27

- Lowercase some unnecessary title casing
- Remove some low-value login/folder-related messages
- A couple of other tweaks

Loops work better when the loop variable changes.

The data isn't important enough to justify the perf hit

Split the -server string in main() to keep the host and port separate
from the get go. Removes some alloca's in the ipc_connect code.

Make them more generic, which means we can ditch a function

Just a simple store that uses one file per message.

On gcc 7:

edit.c: In function ‘edit_user’:
edit.c:391:24: error: ‘sprintf’ writing a terminating nul past the end of the destination [-Werror=format-overflow=]
    sprintf(text, "s%05d", newroom);

poll-epoll.c:20:2: error: implicit declaration of function ‘memset’ [-Werror=implicit-function-declaration]
  memset(&ev, 0, sizeof(ev));

MW now works on FreeBSD

And don't try to use strfry() on it.

On Linux this just makes some implicit includes explicit.

The client now just caches a simple list of gag names that the server
sends it via a new IPC_GAGLIST message.

🔥🔥🤷🔥🔥

Requires build flag tweaks to make container_of() work. (-pedantic
doesn't make much sense with -std=gnu99 anyway).

Mainly for readability but also removes a duplicate strlen() call on the
input text.