* Customization for make targets in build and test phases for AutotoolsPackage
* Updated Blitz++ to use customized make build and test targets
* Removed flake8 error
* Removed make test customization, added make install customization, need to figure out issues with multiple make targets
* Changed build_targets and install_targets to normal attributes
Modifications :
- added EditableMakefile to PackageBase subclasses
- astyle modified as an example
- preliminary hook to stop at a certain phase of install
