Change color component macros are now functions
to rebase
Move function to change color component to init-rainbow-identifiers

Because they are dependent on rainbow-identifiers package
Remove required macros.el file in a configuration layer

Now macros should be defined in funcs.el
Remove unused feature declaration in spacemacs/funcs.el
Move spacemacs/set-font to spacemacs/funcs.el
Add font scaling mini-mode

To easily adjust the font size of a buffer
Add documentation for font scaling mini-mode in readme
Adjust some elisp mode keybindings