[WIP] 4.0@dev

[kohkimakimoto]

Rebuild using laravel (Illuminate) components.
This PR includes a lot of changes.

Design and implementation NOTE:

• RuntimeTask class is too complex class (including a lot of dependences). At now, it has methods to do almost anything in a user defined task. For instance:$task->exec() ,$task->writeln(), $task->call(). So, I want to divide this class to some classes.
• $task->exec() is deprecated. I'm making new syntax. for instance Process::on() that refers to laravel facades.
• $task->writeln() is deprecated. I'm making Output::writeln().

[coveralls]

Coverage decreased (-4.36%) when pulling f14949e on 4.0 into b03b54a on master.

[coveralls]

Coverage decreased (-3.78%) when pulling f7cf055 on 4.0 into b03b54a on master.

[coveralls]

Coverage decreased (-3.58%) when pulling 5b808e7 on 4.0 into b03b54a on master.

[coveralls]

Coverage decreased (-5.96%) when pulling 0994599 on 4.0 into b03b54a on master.

[coveralls]

Coverage decreased (-5.91%) when pulling 0994599 on 4.0 into b03b54a on master.

[coveralls]

Coverage decreased (-7.3%) when pulling d38e547 on 4.0 into b03b54a on master.

[coveralls]

Coverage decreased (-9.22%) when pulling 44f00f2 on 4.0 into b03b54a on master.

[coveralls]

Coverage decreased (-9.22%) when pulling 12eb721 on 4.0 into b03b54a on master.

[coveralls]

Coverage decreased (-9.21%) when pulling 680df64 on 4.0 into b03b54a on master.

[coveralls]

Coverage decreased (-9.22%) when pulling 6192aaf on 4.0 into b03b54a on master.

[coveralls]

Coverage decreased (-9.16%) when pulling 9e70963 on 4.0 into b03b54a on master.

[coveralls]

Coverage decreased (-9.16%) when pulling 9e70963 on 4.0 into b03b54a on master.

[coveralls]

Coverage decreased (-9.74%) when pulling 7b09411 on 4.0 into b03b54a on master.