Created hot fix based on trq-2237
Removed boost from the hotfix.
Merge pull request #191 from adaptivecomputing/4.2.5.h2

4.2.5.h2
trq-2175 Only send out single kill_job to a MOM which will then get propagated. Also fixed a segfault when the exec_hosts string is NULL on a job.
Added in trq-2175 fixes.
trq-2267 another potential deadlock.
TRQ-2237 unlock a mutex before trying to lock the job mutex.
trq-2279 removed boost from the hotfix.
Fixed merge conflict.