Tool for checking that .robot files went through robot.tidy

Tool for checking that .robot files went through robot.tidy

This adds a tool that traverses the specified directories and
either checks that all of the .robot files were passed
through the robot.tidy tool (when "check" is specified as the
command) or performs the "tidying" (when "tidy" is specified
as command). A convenience shell script is provided that
orders the tool to traverse the entire test project and check
(or tidy them if "tidy" argument is given to it) all .robot
files it finds whether they are tidy.

I built this tool in about 2 hours after I got bugged by "did
you run the test through 'tidy'" kinds of requests. When the
"check" version is wired to the validation jobs, this kind of
answers can now be obtained automatically.

Change-Id: I8540f14ba81b55394f2a3285130dea6e945d6649
Signed-off-by: Jozef Behran <jbehran@cisco.com>