grep: move pattern-type bits support to top-level grep.[ch]

diff --git a/RelNotes b/RelNotes
index 5217e8e5543a696660e3f275d9717e0656d786f8..2484b38bbbae654684f65a874653487439f0df2f 120000 (symlink)
--- a/RelNotes
+++ b/RelNotes
@@ -1 +1 @@
-Documentation/RelNotes-1.7.2.3.txt
\ No newline at end of file
+Documentation/RelNotes/1.8.0.txt
\ No newline at end of file