#119: implement some feedback from #996.
cylc gui: fix handling of invalid regexes for filters
unset filtering on bad regex in dot view
Squashed new proc pool changes.
#1014: correctly format cycle point env vars
Record pool size to avoid using multiprocessing.Pool internals.
Allow calendar mode string to be flexible

isodatetime update: d4dd6d95adc9a46f892067f2c99e0e510bb9d9d1.
Remove hard coded calendar type string

Use constants in `isodatetime.data.Calendar` instead.
Merge pull request #1017 from benfitzpatrick/cylc-gui.fix-bad-regex-handling

cylc gui: fix handling of invalid regexes for filters
Merge branch 'master' into 119.iso8601-cycling
Fix import statement
Restored missing "if" statement.
Merge pull request #1022 from matthewrmshin/flexible-calendar-mode

Allow calendar mode string to be flexible
#996: fix bugs picked up in review
#1014: remove redundant rm
Retrieve final proc pool results

Also removes extra blank lines before scheduler methods.
Merge pull request #1020 from benfitzpatrick/1014.initial-final-cycle-point-env-tz

#1014: correctly format cycle point env vars
Merge pull request #1015 from benfitzpatrick/996.feedback-other

#119: implement some feedback from #996.
Merge branch '119.iso8601-cycling' into procpool
Turn off thread ID print.