These changes are motivated by feedback from Tim Hunt (17 October 2011
in the developers chat room). The combination of using an interface, but
then putting all the useful information in public fields, was not good
design of this library. So I am merging the plugin_information interface
and the plugintype_base class into a new abstract class plugininfo_base.
This new class defines the basic API of all information holding
subclasses. This does not change the code, just puts the documentation
closer to the methods they are actually implemented.
This patch introduces new lib/pluginlib.php library that provides
unified access meta-information about all present plugin types. The
library defines plugin_manager singleton that in turn gathers
information about all present plugins and their status. The list of
plugins can be rendered either as plugins check table or plugins control
panel.
This makes print_plugins_table() function obsolete and because it is not
expected to be called by any contrib plugin, the function is removed.
CSS for the legacy table generated by print_plugins_table() is cleaned
up.