-I supports shell globs

Fixes #1

Author: mgarciaisaia

example/Makefile

@@ -1,6 +1,6 @@
 .PHONY: all clean
 
-MPP = ../bin/mpp -Iassets/css -Iassets/js
+MPP = ../bin/mpp -Iassets/*
 
 all: css/root.css js/root.js
 

src/resolver.cr

@@ -21,7 +21,7 @@ class Resolver
   end
 
   def add(paths : Array(String))
-    @search_paths.concat(paths.map { |path| File.expand_path(path) })
+    paths.each { |path| Dir.glob(path) { |file| @search_paths << file } }
   end
 
   private def find(path)