Refactor and code cleanup of filtering

started working on this with the idea of fixing #1623, although I
realized that this was actually just a documentation issue around
a toml eccentricity.

closes #1623

filter/filter.go

@@ -10,16 +10,16 @@ type Filter interface {
 	Match(string) bool
 }
 
-// CompileFilter takes a list of string filters and returns a Filter interface
+// Compile takes a list of string filters and returns a Filter interface
 // for matching a given string against the filter list. The filter list
 // supports glob matching too, ie:
 //
-//   f, _ := CompileFilter([]string{"cpu", "mem", "net*"})
+//   f, _ := Compile([]string{"cpu", "mem", "net*"})
 //   f.Match("cpu")     // true
 //   f.Match("network") // true
 //   f.Match("memory")  // false
 //
-func CompileFilter(filters []string) (Filter, error) {
+func Compile(filters []string) (Filter, error) {
 	// return if there is nothing to compile
 	if len(filters) == 0 {
 		return nil, nil