patch 7.4.1855
Problem:    Valgrind reports memory leak for job that is not freed.
Solution:   Free all jobs on exit.  Add test for failing job.
diff --git a/src/proto/channel.pro b/src/proto/channel.pro
index 5dc5121..60b68f0 100644
--- a/src/proto/channel.pro
+++ b/src/proto/channel.pro
@@ -50,6 +50,7 @@
 void free_job_options(jobopt_T *opt);
 int get_job_options(typval_T *tv, jobopt_T *opt, int supported);
 channel_T *get_channel_arg(typval_T *tv, int check_open, int reading, int part);
+void job_free_all(void);
 int set_ref_in_job(int copyID);
 void job_unref(job_T *job);
 int free_unused_jobs_contents(int copyID, int mask);