update git config

gitconfig

@@ -1,6 +1,10 @@
+# vi:syntax=gitconfig
 [core]
 excludesfile = ~/.gitignore
 
+#[init]
+#    templatedir = ~/.git_template
+
 [pull]
 ff = only
 rebase = true
@@ -9,12 +13,24 @@ rebase = true
 ff = only
 tool = vimdiff2
 
+[mergetool]
+keepBackup = false
+
 [diff]
 tool = vimdiff2
 
+[difftool]
+prompt=true
 [rebase]
 autostash = true
 autosquash = true
+squash = true
 
 [log]
 abbrevcommit = true
+
+[format]
+#pretty = format:%C(yellow)commit %h%Cred%d %Creset%nAuthor: %Cblue%>(12)%an%n%CgreenDate: %ar%Creset%n%n%B
+
+[alias]
+showtool = "!showci () { rev=${1:-HEAD}; git difftool $rev~1 $rev; }; showci $1"