Some refactoring and code cleanning.

Started implementing dry run.
Some more minor refactoring.
Added more "dryrun" parameters.
Added dryrun to git()
Dryrun implemented for launch() and launch_pipeline()
Some lines of code removed.

Started coding the tests.
* Added new debug config.
* CXX flags of debug/release configs fixed.
* Fixed problem with magrit::success() exception.
* build-cat test almost done.
Implemented cat/log tests.