lang: funcs: core: Drop unnecessary core prefix from imports

This unbreaks the mcl bindata code. Of course we could change the parser
to allow this prefix, but this is cleaner. The packages still have a
core prefix, which it seems we could also remove, but this isn't
particularly important for anything.

lang/funcs/core/core.go

@@ -19,11 +19,11 @@ package core
 
 import (
 	// import so the funcs register
-	_ "github.com/purpleidea/mgmt/lang/funcs/core/coredatetime"
+	_ "github.com/purpleidea/mgmt/lang/funcs/core/datetime"
-	_ "github.com/purpleidea/mgmt/lang/funcs/core/coreexample"
+	_ "github.com/purpleidea/mgmt/lang/funcs/core/example"
-	_ "github.com/purpleidea/mgmt/lang/funcs/core/corefmt"
+	_ "github.com/purpleidea/mgmt/lang/funcs/core/fmt"
-	_ "github.com/purpleidea/mgmt/lang/funcs/core/coremath"
+	_ "github.com/purpleidea/mgmt/lang/funcs/core/math"
-	_ "github.com/purpleidea/mgmt/lang/funcs/core/coreos"
+	_ "github.com/purpleidea/mgmt/lang/funcs/core/os"
-	_ "github.com/purpleidea/mgmt/lang/funcs/core/corestrings"
+	_ "github.com/purpleidea/mgmt/lang/funcs/core/strings"
-	_ "github.com/purpleidea/mgmt/lang/funcs/core/coresys"
+	_ "github.com/purpleidea/mgmt/lang/funcs/core/sys"
 )