evilify: Add dotspacemacs-evilify-blacklist

[justbur]

This is a list of modes that are prevented from entering evilified state
by default.

One possible solution for #3022

[justbur]

@mbertheau try this and see if it works for you

[mbertheau]

@justbur that works as advertised.

[person808]

This would need tests.

[mbertheau]

I tried dotspacemacs-evilify-blacklist for a while and I found it really irritating that SPC doesn't work, which is the universal way out (for example to another buffer). I realize that that probably means that in a final solution we could still deviate from on-screen docs for SPC.

Will try dotspacemacs-dont-evilify now.

[mbertheau]

SPC doesn't work with dont-evilify either, but my understanding improved greatly :)

I'm running with light evilification now mbertheau@11e9c56.

[justbur]

Answered the last part about SPC here

[justbur]

Not needed for magit after #3578