Feature finish squash parameter

Adding an optional (false by default) -S option to 'git flow feature finish' to allow squashing
the commit

git-flow-feature

@@ -44,7 +44,7 @@ PREFIX=$(git config --get gitflow.prefix.feature)
 usage() {
 	echo "usage: git flow feature [list] [-v]"
 	echo "       git flow feature start [-F] <name> [<base>]"
-	echo "       git flow feature finish [-rFkD] [<name|nameprefix>]"
+	echo "       git flow feature finish [-rFkDS] [<name|nameprefix>]"
 	echo "       git flow feature publish <name>"
 	echo "       git flow feature track <name>"
 	echo "       git flow feature diff [<name|nameprefix>]"
@@ -232,6 +232,7 @@ cmd_finish() {
 	DEFINE_boolean rebase false "rebase instead of merge" r
 	DEFINE_boolean keep false "keep branch after performing finish" k
 	DEFINE_boolean force_delete false "force delete feature branch after finish" D
+    DEFINE_boolean squash false "squash feature during merge" S
 	parse_args "$@"
 	expand_nameprefix_arg_or_current
 
@@ -312,7 +313,13 @@ cmd_finish() {
 	if [ "$(git rev-list -n2 "$DEVELOP_BRANCH..$BRANCH" | wc -l)" -eq 1 ]; then
 		git merge --ff "$BRANCH"
 	else
-		git merge --no-ff "$BRANCH"
+        if noflag squash; then
+		    git merge --no-ff "$BRANCH"
+        else
+            git merge --squash "$BRANCH"
+            git commit
+            git merge "$BRANCH"
+        fi
 	fi
 
 	if [ $? -ne 0 ]; then
@@ -353,7 +360,7 @@ helper_finish_cleanup() {
 			git branch -d "$BRANCH"
 		fi
 	fi
-
+t 
 	echo
 	echo "Summary of actions:"
 	echo "- The feature branch '$BRANCH' was merged into '$DEVELOP_BRANCH'"