template, data and build functions are kept in single package file, on_fail and on_success callbacks, check for package integrity, packages have different names so can be kept simultaneously
Revert "template, data and build functions are kept in single package file, on_fail and on_success callbacks, check for package integrity, packages have different names so can be kept simultaneously"
Will add it as separate module to keep backward compatibility

This reverts commit feece349f7a8729cc753265e749eed83db4e1925.
package logic moved to beampkg, keeping original beambag
test added for beampkg, Dmitry's notes are considered
review related fixes
more code reuse, propadata copied to beambag as packaging part of project
del dir with del_dir
erlang:send_after in beambag too
Merge pull request #5 from virtan/master

Package-based mechanism