[hackers] [farbfeld] Also print extra warnings || Laslo Hunhold

[git]

commit f22282e99a963f5935ea68a583cc7d928a787ce1
Author:     Laslo Hunhold <d...@frign.de>
AuthorDate: Wed Apr 12 23:36:06 2017 +0200
Commit:     Laslo Hunhold <d...@frign.de>
CommitDate: Wed Apr 12 23:36:06 2017 +0200

    Also print extra warnings

diff --git a/config.mk b/config.mk
index 4cd5ce2..b6b0ce4 100644
--- a/config.mk
+++ b/config.mk
@@ -9,7 +9,7 @@ MANPREFIX = ${PREFIX}/man
 
 # flags
 CPPFLAGS = -D_DEFAULT_SOURCE
-CFLAGS   = -std=c99 -pedantic -Wall -Os
+CFLAGS   = -std=c99 -pedantic -Wall -Wextra -Os
 LDFLAGS  = -s
 
 png2ff-LDFLAGS = -lpng