Redesign def-project-mode! macro & update references
Redesign def-project-mode! macro & update references

+ Renamed :init to :on-load (run once, the first time the project mode
  is activated).
+ New properties :on-enter FORM and :on-exit FORM (run each time the
  mode is enabled or disabled, respectively).
+ New property :hooks HOOKS (automatically add HOOKS to mode-hook).

UndeadKernel/emacs_doom,hlissner/doom-emacs,hlissner/.emacs.d,hlissner/.emacs.d,hlissner/doom-emacs,aminb/.emacs.d,hlissner/doom-emacs,hlissner/.emacs.d,hlissner/.emacs.d,aminb/.emacs.d,hlissner/.emacs.d,UndeadKernel/emacs_doom,UndeadKernel/emacs_doom,UndeadKernel/emacs_doom,aminb/.emacs.d,hlissner/doom-emacs,UndeadKernel/emacs_doom,UndeadKernel/emacs_doom,hlissner/doom-emacs,hlissner/.emacs.d,UndeadKernel/emacs_doom,hlissner/.emacs.d,aminb/.emacs.d,aminb/.emacs.d,hlissner/.emacs.d,aminb/.emacs.d,hlissner/doom-emacs,aminb/.emacs.d,aminb/.emacs.d,hlissner/doom-emacs