diagram improvement: (1) no more "empty boxes" and (2) tables dataflown from a box are shown in their boxes

Added coloured barchart display option and jobs/data display option (no big data checks, use with care on small examples).
'Pad' is now configurable from JSON.
Beware: JSON config options have moved around!

added command line options -submit_stdout_file and -submit_stderr_file to peek into submission output/error streams

fixed a bug in computing num_required_workers according to the new rules (thanks Matthieu for reporting)

bugfix: do not proceed with negative numbers of workers for submission (thanks to Matthieu for reporting)

fix: 'msg' view now displays the analysis of the job (which is fixed), not that of worker (which may change with time)

changed the meaning of 'num_required_workers' to "total estimated number of workers needed for this analysis" ( 'num_running_workers' is now included in it )

change of default behaviour: hive_capacity is now off by default (=NULL); setting hive_capacity=0 or analysis_capacity=0 stops scheduling AND specialization to a particular analysis

cleanup: removed runnable(), output() and parameters() subroutines from Process as no longer used by Compara

removed the "compile_module_once" option as the only way to compile modules now is once after specialization

secutiry: make sure stringify() always produces perl-parsable structures, so that global settings of Data::Dumper do not affect its results (thanks to Uma and Matthieu for reporting)

added a new per-analysis "analysis_capacity" limiter for cases where users want to limit analyses independently

switch the Scheduler to using universal Limiter objects (cleaner code, more precise computation and should allow for expansion)

moved pending adjustment out of the main scheduling subroutine, which simplified the logic and improved readability

Introduced a new 'NO_ROLE' cause_of_death for failures during specialization (not so much of an error, really!)

bugfix: avoid specializing in an otherwise BLOCKED analysis that is temporarily in SYNCHING state (thanks to Kathryn for reporting)

(multi-meadow scheduler) restrict the set of analyses that a worker with a given meadow_type can specialize into

bugfix: if re-running a job that creates a semaphored group, we no longer die (thanks Miguel for reporting)

Added API and schema support for analysis_base.meadow_type / Analysis->meadow_type(), which will be NULL/undef by default