Recent support for subdirs under src misbehaves with manpages

[jimklimov]

Recently support was added to track nested source directories with zproject. As a consequence, the $(name) variable holds the complete sub-path (e.g. something/progname) and the $(name:c) has its slashes substituted to underscores. This was considered with manpage generation, where clumsily the classes have the dirname prefixed; however it breaks the "main" programs' manpages, or rather packaging thereof.

The following code installs the manpage:

install something/prog.1 .../usr/share/man/man1/

into the circumstantially correct location (the install tool drops the leading subdir name), and then the packaging info refers to a usr/share/man/man1/something/prog.* (at least for SPEC files) which breaks - the "something" should not be there.

Possibly the best way to address this would be to introduce a GSL modifier like $(name:basename) to chop off path components, or to conjure up a spell for GSL string manipulation (substr and some sort of search for the last path separator, if any).