Adding an S-expression structured output printer.

This commit adds a structured output printer for Lisp
S-Expressions. Later commits will use this printer in notmuch search,
show and reply.

The structure is the same as json, but:
- arrays are written as lists: ("foo" "bar" "baaz" 1 2 3)
- maps are written as p-lists: (:key "value" :other-key "other-value")
- true is written as t
- false is written as nil
- null is written as nil

[ whitespace changes by db ]

1 files changed, 1 insertions, 0 deletions

diff --git a/Makefile.local b/Makefile.local
index 2b919465..0db1713e 100644
--- a/Makefile.local
+++ b/Makefile.local
@@ -270,6 +270,7 @@ notmuch_client_srcs =		\
 	notmuch-tag.c		\
 	notmuch-time.c		\
 	sprinter-json.c		\
+	sprinter-sexp.c		\
 	sprinter-text.c		\
 	query-string.c		\
 	mime-node.c		\