Instead of using the more rollup-tolerant config for all files, make the
configuration stricter by default but lower in grunt for yui modules.
This means that manual runs (prechecker) or editor integrations will
flag up the errors as well as grunt.
Also add ignore lines to the core files so that eslint isn't noisy when
not running with grunt.
There are numerous bugs with this new module to do with showing the currently selected date,
random changes in the selected dates, showing multiple selected dates and css errors.
This reverts commit 1d128663f6.
This reverts commit 4a521e6596.
The aria-live="polite" attribute is incorrectly added to the fieldset,
causing the entire fieldset to be read out on change in some browsers. This
is unnecessary.
It also does not announce the current state of the fieldset (collaped or
open) and should.
