display:__init__: Make display subsystem a module

Add __init__.py to the display subsystem.

Signed-off-by: Guofeng Liu <lgf612@sina.com>
test:test_output: Add new test for colored output

A small demo for how to use PrintColor highlighting some
information. Currently only support Linux host.

Signed-off-by: Guofeng Liu <lgf612@sina.com>
display:output: Remove the code for test

The test for features in output has been moved to the test
subsystem. Remove the test code from output.

Signed-off-by: Guofeng Liu <lgf612@sina.com>
date: format all returned dates as string.

1) Add _formatRetDate() to format date to string.
2) Formated all returned dates to strings.

Signed-off-by: Zhengwang Ruan <ruan.zhengwang@gmail.com>
data: Move data.py to dataMgr subsystem.

1) Move data.py to dataMgr subsystem in order to achieve better
   clearness in code structure.
2) Fix all error to import data module caused by 1).

Signed-off-by: Zhengwang Ruan <ruan.zhengwang@gmail.com>
date: add two methods and update code.

1) Add getDateNextDays() to return the date by next number of days.
2) Add getDatePrevDays() to return the date by previous number
   of days.
3) Rename _formatRetDate() to _dateToString().
4) Update all date comparison uising _dateToString().

Signed-off-by: Zhengwang Ruan <ruan.zhengwang@gmail.com>
test:test_date: add tests for new methods.

Add tests for getDateNextDays() and getDatePrevDays().

Signed-off-by: Zhengwang Ruan <ruan.zhengwang@gmail.com>
Merge branch 'winf-dev' into zhengwang-dev