Apply level zero (no section) defaults for suite.rc.

For suite definitions we do not load all default values at once, in
order to leave a sparse runtime structure for efficient inheritance.
However, in loading defaults for everything but [runtime] I had
neglected to load the top level non-section defaults (just title and
description).
Fixed reload of async tasks in mixed suites, and sequential tasks.
Merge pull request #637 from hjoliver/fix-two-reload-bugs

Fixed reload of async tasks in mixed suites, and sequential tasks.
cylc/cylc#602: gcylc: add ungrouped usercfg
fix oops in previous commit.
.gitignore: add site configuration related entries
Merge pull request #636 from hjoliver/suiterc-level0-defaults

Apply level zero (no section) defaults for suite.rc.
Merge pull request #641 from matthewrmshin/fix-gitignore

.gitignore: add site configuration related entries
Merge pull request #640 from benfitzpatrick/gcylc.user-rc-ungroup

#602: gcylc: add ungrouped usercfg
Merge branch 'master' into 212.site-host-pattern

Conflicts:
	lib/cylc/cfgspec/suite_spec.py