mutt 1.5.22

The update required a few changes:

+ Two Debian patches had moved, so I updated their URLs.
+ The sidebar patch no longer applies. Until it's updated, if it ever is,
  I removed the option. That means the formula no longer needs to check if
  sidebar and ignore-thread are installed together, so I removed the block
  of code that checks for that edge condition.

Closes #23590.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
spidermonkey: use stdenv to ensure libc++
libmpdclient: add doxygen dep to HEAD