Update TbDataColumn.php

Use icon depends on sort direction
Added new assets package for `Bootstrap Timepicker` widget
Corrected wrong generation of HTML IDs for TimePicker.
Pushed the rendering of wrappers around timepicker down from the ActiveForm to TimePicker widget itself.
Merge pull request #665 from zhalinskiy/patch-1

Update TbDataColumn.php
Marked the widgets which has an end-user documentation page.
Marked the widgets which has an end-user documentation page.
Removed the broken `TbExtendedTooltip` from codebase (too specific, database-bound).
re #511
Merge remote-tracking branch 'origin/master'

Conflicts:
	CHANGELOG.md
	src/components/packages.php
Responsive CSS are the default now.
re #556