Add links to all reservation notes

[orenyk]

See equipment object notes for examples.

[orenyk]

We should probably wait until #273 is merged in to capitalize on the methods added in that branch (i.e. #md_link). We can also use those links in e-mails if we're using Markdown to evaluate custom e-mail text from the App Configs.

[orenyk]

Started working on this; I've made all of the links absolute so we can use markdown rendering in e-mails as well, and added markdown rendering to the flash too (similar to announcements, see #1027). I'll wrap this up then open a PR.

[orenyk]

Also realized that the archiving of a reservation was not being noted in equipment objects. This has been resolved.