Improve runtime database query functions

No longer susceptible to `.next()[0]` problem.
Merge pull request #1067 from matthewrmshin/improve-db-query-funcs

Improve runtime database query functions
Use natural sort order in graph tests.
Don't reload tasks in the 'ready' state.
Merge pull request #1072 from hjoliver/graph-test-sort-order

Use natural sort order in graph tests.
Merge pull request #1074 from hjoliver/reload-adjustment

Don't reload tasks in the 'ready' state.
Restructure suite run time log/job/ and work/

Directory structure now looks like:
* `log/job/CYCLE/TASK/{01,02,...,NN}/{job,job.out,job.err,job.status}`
* `work/CYCLE/TASK/`

which should make it easier to archive the log for the whole cycle or to
housekeep all the work files of a given cycle.

`log/job/CYCLE/TASK/NN` is a symbolic link that points to the job log
directory of the latest submit for `TASK.CYCLE`.
log/work restructure: fix combo log view

It was displaying only the base names of the files, which would not be
very meaningful when we have multiple submits.

Rename CYCLE_TIME to CYCLE_POINT in `cylc.cfgspec.suite`.
Log/work restructure: fix test
Script to upgrade a pre cylc-6 suite run dir.
Update to isodatetime-2014.08.0
TimeInterval renamed Duration
Merge pull request #1078 from matthewrmshin/isodatetime-2014.08.0

Isodatetime 2014.08.0
Merge pull request #1069 from matthewrmshin/log-work-restructure

Restructure suite run time log/job/ and work/
Merge branch 'master' into remove-trailing-blank-lines