Revert "Parse CLI args after dotspacemacs/init"
This reverts commit 0a35502de4.
We cannot delay the parsing of CLI params since we need their values
early during the loading process (i.e. debug info).
Replace the previous commit with a new variable `spacemacs-insecure`
which takes the value of --insecure boolean parameter.
--no-layer: desactive all the layers except the distribution layer
--distribution: allow the change temporarily the distribution
example
Start emacs with spacemacs-base and no layers:
emacs --no-layer --distribution spacemacs-base
Note that any non Emacsy command line parameter and non processed
command line parameter (that is unknown from Spacemacs) will hide the
home buffer. This should be good enough.
Fixes#4057
