* Select & Cascader: add chalk theme

* Select / Cascader: fix test

* only emit user change for timepicker and datepicker

* Test: remove custom timeout

# Conflicts:
#	examples/docs/en-US/input.md
#	examples/docs/zh-CN/input.md

* TimePicker: add chalk theme

* minor style fixes

* Dropdown: add chalk theme

* Dropdown: update doc

* Update dropdown.md

* Tooltip: update zh-CN doc

* Tooltip: update en doc

* Autocomplete: update docs

* when pressing enter without a selection, select the currently entered text and clear selections.

* added "select-when-unmatched" flag

* restored "???" to "-"

* Message Box: add chalk theme

* Message Box: doc fix

* Message Box: change prop name into center

# Conflicts:
#	packages/date-picker/src/panel/time.vue

* Playground: bump to new theme

* Tree: update chalk theme

* update doc

* Update var.scss

* Popover: add chalk theme

* Popover: add chalk theme