patch 8.0.0167: str2nr()/str2float() fail with negative values

Problem:    str2nr() and str2float() do not always work with negative values.
Solution:   Be more flexible about handling signs. (LemonBoy, closes #1332)
            Add more tests.
diff --git a/src/version.c b/src/version.c
index f5327cc..c74052d 100644
--- a/src/version.c
+++ b/src/version.c
@@ -765,6 +765,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    167,
+/**/
     166,
 /**/
     165,