refactor key bindings for applications to provide additional room for
applications and use lower case characters.
Move calc-dispatch to `SPC a *`
Relates to #13503
This reverts commit 29c78ce841 and all other fixes
that have been made afterwards.
The motivation is that use-package is seen by many as a replacement for
`require`. Is use-package always defer the loading of packages then is breaks
this use case, this does not respect POLA so even if it was making Spacemacs
loading faster (up to 3s faster on some startup on my machine) we just cannot
use it, it would be irresponsible. Spacemacs should be easy to use, loading
performance will come with time but it is not a priority.
I feel like we should start from scratch on this one and carefully choose the
defaults.
Also this settings is a very personal setting so if we make some buffers
useless we must have a consensus on it. Marking all special buffers starting
with `*` as useless is too aggressive and make Spacemacs less POLA since two
consecutive press on SPC TAB may not revert to the original buffer.
Helm seems to treat "!" specially in pattern matching, so having a ! in
the pattern string when traversing directories is problematic. This
change fixes#2737, because as far as I can tell "+" has no special
meaning in a helm pattern.
Of course, we can choose a different character, but I'm fond of "+" as
representing "more layers here".
