[git] Fix git stash alias,set default pull options

Fixed git stash alias (gsta) not correctly detecting zsh shell for git
version guessing.

Set default options to automatically rebase on pull, automatically prune
on fetch, and automatically stash and squash on rebasing.

Also made git diff highlight moved code.

git/.config/git/config

@@ -10,6 +10,23 @@
 [alias]
   ignore = "!gitignore -f"
   pushmerge = "push -o merge_request.merge_when_pipeline_succeeds" # see https://docs.gitlab.com/ce/user/project/push_options.html#merge-when-pipeline-succeeds-alias
+[commit]
+  # sign commits as me
+	gpgsign = true
+	# Always show diff when preparing commit message
+	verbose = true
+[fetch]
+  # remove references to non-existent remote branches
+	prune = true
+[pull]
+	rebase = true # always rebase on pulling, obviates merge commits
+[diff]
+	colorMoved = zebra # also color stuff that has simply been moved, in a classy zebra-color
+[rebase]
+	autostash = true
+	autoSquash = true
+# Make use of git urls for git{lab,hub}, but only do so for pushing
+# since pulling will create troubles with some applications
 [url "git@github.com:"]
   pushInsteadOf = "https://github.com/"
 	pushInsteadOf = "http://github.com/"
@@ -17,8 +34,3 @@
 [url "git@gitlab.com:"]
   pushInsteadOf = "https://gitlab.com"
 	pushInsteadOf = "http://gitlab.com"
-[commit]
-  # sign commits as me
-	gpgsign = true
-	# Show diff when preparing commit message
-	verbose = true

git/.config/sh/alias.d/git.sh

@@ -47,14 +47,19 @@ if exist git; then
 
   alias gst='git status'
 
-  if [ "$0" = "/bin/zsh" ]; then
+  # if git is at least version 2.13, we can use git stash push
+  # in shells other than zsh, simply fall back to save
+  case "$(ps -cp "$$" -o command="")" in
+  *zsh*)
     autoload -Uz is-at-least
     if is-at-least 2.13 "$(git --version 2>/dev/null | awk '{print $3}')"; then
       alias gsta='git stash push'
     else
       alias gsta='git stash save'
     fi
-  fi
+    ;;
+  *) alias gsta='git stash save' ;;
+  esac
   alias gstp='git stash pop'
   alias gstl='git stash list'
 fi