-Add settings file and load it from main script

-Change enable variable name so that it matches current naming convention
-Add Trailing Space commands to the command palette so that delete and toggle can be called even without shortcuts defined

trailing_spaces.sublime-settings

@@ -0,0 +1,10 @@
+{
+	// Color is determined by scope
+	"trailing_spaces_highlight_color" : "invalid",
+
+	// Max file size to search
+	"trailing_spaces_file_max_size"   : 1048576,
+
+	// By default plugin is enabled or disabled (true|false)
+	"trailing_spaces_enabled"         : true
+}