add ./logerrit resubmit

resubmit creates a new Change-Id for the current change and thus allow to submit
changes for review on release branches that were already reviewed on master.

Also hint advanced users to 'git review' which requires some more setup, but
should make things easier for regular users.

Getting this functionality into 'git review' would be likely help adoption too
-- and in python there is some sane errorchecking possible.

Change-Id: Ibea6bbfe747af160728b838c6ee236fd8f89671d

logerrit

@@ -31,13 +31,34 @@ ask_tristate() {
 
 }
 
+submit() {
+		BRANCH=$1
+		if test -z "$BRANCH"
+		then
+			BRANCH=`git symbolic-ref HEAD 2> /dev/null`
+			BRANCH="${BRANCH##refs/heads/}"
+			if test -z "$BRANCH"
+			then
+				echo "no branch specified, and could not guess the current branch"
+				exit 1
+			fi
+			echo "no branch specified, guessing current branch $BRANCH"
+		fi
+		git push $GERRITURL HEAD:refs/for/$BRANCH
+}
+
 case "$1" in
 	help)
 		echo "Usage: ./logerrit subcommand [options]"
+		echo "simple and basic tool to interact with LibreOffice gerrit"
 		echo "subcommands:"
 		echo "             test                    test your gerrit setup"
-		echo "             submit [BRANCH]      submit your change for review to a branch"
+		echo " --- for submitters:"
+		echo "             submit [BRANCH]         submit your change for review"
+		echo "             resubmit [BRANCH]       create a new Change-Id and submit your change for review"
+		echo "                                     (yes, this modifies your last commit)"
 		echo "             nextchange [BRANCH]     reset branch to the remote to start with the next change"
+		echo " --- for reviewers:"
 		echo "             checkout CHANGEID       checkout the changes for review"
 		echo "             pull CHANGEID           pull (and merge) the changes on current branch"
 		echo "             cherry-pick CHANGEID    cherry-pick the change on current branch"
@@ -45,6 +66,8 @@ case "$1" in
 		echo "             review [CHANGEID]       interactively review a change (current one if no changeid given)"
 		echo "             query ....              query for changes for review on project core"
 		echo "             <any other gerrit command>"
+		echo "advanced users should consider using git review instead:"
+		echo "http://wiki.documentfoundation.org/Development/GitReview"
 		exit
 	;;
 	test)
@@ -58,19 +81,11 @@ case "$1" in
 		fi
 	;;
 	submit)
-		BRANCH=$2
-		if test -z "$BRANCH"
-		then
-			BRANCH=`git symbolic-ref HEAD 2> /dev/null`
-			BRANCH="${BRANCH##refs/heads/}"
-			if test -z "$BRANCH"
-			then
-				echo "no branch specified, and could not guess the current branch"
-				exit 1
-			fi
-			echo "no branch specified, guessing current branch $BRANCH"
-		fi
-		git push $GERRITURL HEAD:refs/for/$BRANCH
+        submit $2
+	;;
+    resubmit)
+        git log -1 --pretty=%B | grep -v ^Change-Id: | git commit --amend -F -
+        submit $2
     ;;
 	nextchange)
 		if test -n "`git status -s -uno`"