prepare internal module to the recoder implementation. + code cleanup

- add the methods to initalize the capture device
- add function init_in wich must be called before capture sound
- add struct CaptureContext, no methods only for internal use, returned by init_in,
useful to be shared between task.
- clean code: trailing whitespace + indent
change CaptureContext to RecordContext.
implement basic recorder

- try to make a kiss api -> start / stop / save_to_file
- can be use in its own task
- need a RecordContext to be created
- next -> get a SoundData created by a Recorder and be able to play it in a Sound.
add the example to the makefile
Merge pull request #3 from JeremyLetang/recorder

begin recorder implementation