patch 9.0.0510: Chatito files are not recognized

Problem:    Chatito files are not recognized.
Solution:   Add a pattern for Chatito files. (closes #11174)
diff --git a/runtime/filetype.vim b/runtime/filetype.vim
index 9af7880..78d723c 100644
--- a/runtime/filetype.vim
+++ b/runtime/filetype.vim
@@ -299,6 +299,9 @@
 " ChaiScript
 au BufRead,BufNewFile *.chai			setf chaiscript
 
+" Chatito
+au BufNewFile,BufRead *.chatito			setf chatito
+
 " Comshare Dimension Definition Language
 au BufNewFile,BufRead *.cdl			setf cdl
 
diff --git a/src/testdir/test_filetype.vim b/src/testdir/test_filetype.vim
index fa641f1..03384b6 100644
--- a/src/testdir/test_filetype.vim
+++ b/src/testdir/test_filetype.vim
@@ -108,6 +108,7 @@
     \ 'ch': ['file.chf'],
     \ 'chaiscript': ['file.chai'],
     \ 'chaskell': ['file.chs'],
+    \ 'chatito': ['file.chatito'],
     \ 'chill': ['file..ch'],
     \ 'chordpro': ['file.chopro', 'file.crd', 'file.cho', 'file.crdpro', 'file.chordpro'],
     \ 'cl': ['file.eni'],
diff --git a/src/version.c b/src/version.c
index 22db890..d7d5bd3 100644
--- a/src/version.c
+++ b/src/version.c
@@ -700,6 +700,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    510,
+/**/
     509,
 /**/
     508,