LSF-0.5 - load various LSF modules

Changes for version 0.5

LSF::JobInfo is now defunct. The information obtained from the bjobs command is expunged from the LSF logs far too quickly to be reliably available in a long running batch environment. Replacing it is LSF::JobHistory which calls and parses the bhist command.
Removed the jobs_with_status method from the LSF::JobManager module since this didn't have a good rationale behind it and the exit status is now obtainable from the LSF::JobHistory object.
Added a clear method to the LSF::JobManager class so that the jobs in a job manager can be cleared and it can be reused.
Added a history method to the LSF::Job class so that an LSF::JobHistory object can be obtained for a job.
Removed the info method from the LSF::Job class
The LSF::JobManager->wait_all_children method now uses LSF::JobHistory to pre-cache the results of the bhist command for each job. There are hugely significant performance benefits to calling a single bhist command line for all jobs as opposed to once for each job.