fix the bug when edit is empty,could not input by keyboard or mouse.
Merge remote-tracking branch 'remotes/origin/master'

Conflicts:
	components/rtgui/widgets/edit.c
Merge remote-tracking branch 'remotes/remote/master'
Merge branch 'master' of https://github.com/nongxiaoming/RTGUI
widgets:fix the box layout bug for horizontal layout
widget:add the on_changed event to the filelist_view
dialog:add the filedialog
add the filedialog test case
Merge pull request #61 from nongxiaoming/master

add the filedialog