add missing runtime deps to ALL core packages, add getrealdeps script (#7472)

* gcc: add missing zlibpkg dep

* add getrealdeps script

* add color

* suggested changes from @supechicken

* suggested changes

* fix verbiage

* add NOCOLORS option

* use read in lieu of head, and do not check nonexistent files

* Exit early if wrong package name is given.

* Add some quick exit code

* Allow for pkg.rb in getrealdeps and also add deps to all core packages

* fix lint error

* fix zlibpkg

* cleanup gcc deps

* move filecmd to be a ruby dependency

* fix llvm deps

* lint fix

* update more deps

* make sure package is installed before checking for deps

* add more deps

* change verbiage

* add more deps

* more dep updates

packages/symlinks.rb

@@ -23,6 +23,8 @@ class Symlinks < Package
      x86_64: '39fe5a53a1c557aa71cfd6d7760e069c0421931e3e5345c57696e1cf79bf8e39'
   })
 
+  depends_on 'glibc' # R
+
   def self.patch
     system('for i in `cat debian/patches/series`; do patch -p 1 < debian/patches/$i; done')
     system "sed -i 's,/usr/local,#{CREW_DEST_PREFIX},g' Makefile"