Implementation of "check_for_brew" function ++

-Added “check_for_brew” function
-Added strings that can help the user if Brew is not installed
-Added Brew checking related variables
-Implemented “check_for_brew” in “main”
-Initial implementation of Colors
-Removal of “unsufArgs” string as it was useless
-Added “-e” argument in many “echo” calls (needed for coloring)
-Used the :- variable substitution when installing libs
Better arguments handling ++

-Revamped “check_args”, now named “check_stuff”. Relieves me from
headaches I was going to have
-Better argument checking system: more relentless, checks better if an
argument is a valid installable lib (or a “help”)
-Checks for Homebrew. No Homebrew? It’ll tell you how to install it.
-Checking systems for connections and requirements now brought into
“check_stuff”
-Added “noInternet” condition for when installing Required kegs
-Added system of ignoring non-existent libraries
-Corrected “usage” string
-Indicated that Xcode+tools must be installed before installing Brew