Before the reserved
project, there may be one or two "qualifiers", that
is identifiers or other reserved words, to qualify the project.
The current list of qualifiers is:
abstract: qualify a project with no sources. An abstract project must have a declaration specifying that there are no sources in the project, and, if it extends another project, the project it extends must also be a qualified abstract project.
standard: a standard project is a non library project with sources.
aggregate: for future extension
aggregate library: for future extension
library: a library project must declare both attributes
configuration: a configuration project cannot be in a project tree.