* Tag: add tag click event handle

* Tag: add doc and unit test.

* remove sponsor duotai

* recover douhui

i18n: add missing Catalan translations

Document: Fix a document difference

Checkbox: refine style

chore: use shadow CDN and fix typo

When the selected week spans across two years (e.g. 2018-12-30 2019-01-05),
they should be highlighted in both month tables.

fix regression introduced in pr #13266, where popper arrow is hidden

Pagination: input max value won't be less than 1 (#13727)

Upload: add url prop to upload file when list-type changed (#13771)

Carousel: stop timer before component destroyed (#13820)

* Table: fix empty text vertical alignment issue on IE10+

* Table: add a comment to IE-specific fixes

* Fix issue with popover displaying on focus when configuration is for it to show on hover.
Fix issue with popover timer still running when button clicked and parent element no longer visible (e.g. keepalive component).

* Updated to pass tests

* Correct documentation for el-date-picker

* Changes as per ziyoung review

Allows `children` and `disabled` to be undefined