rdoc: don't specify a full path for included and excluded files for RDoc

The RDoc rake task has a bug, in which providing absolute paths
for the include and exclude sets causes the html file to be (wrongly)
generated in the source directory instead of in the output directory.
display full documentation generation exception backtrace if rake tracing is enabled
move the inherited_enumerable code to a separate Utilrb::Models module
Merge remote-tracking branch 'autobuild/stable' into next
Merge remote-tracking branch 'autobuild/next'
dsl: use __send__ instead of send to allow sandboxes to be used as main objects
logger: make sure that make_own_logger propagates its changes in the hierarchy
dsl: use __send__ instead of send to allow sandboxes to be used as main objects
implement a workaround for Qt::Variant.from_value in qtruby

The issue with Qt::Variant.from_value(Object.new) is that it breaks. Often.

This method is pure-ruby, does not rely on anything fancy, but requires a bit
of thinking, as one must give a proper lifetime object to keep the ruby object
alive.

Note that if the goal is to get ruby objects across signal/slots, there is no
need for a lifetime object, as the QVariant will be this lifetime object.
add doc? method
checks if a documentation can be generated by yard or rdoc
qt: fix Variant.from_ruby / to_ruby for object_id's that are bigger than 31bits
qt: remove debugging output
doc: add clubber and rebuild task
doc: add clubber and rebuild task
doc: add clubber and rebuild task
add ThreadPool implementation.

usage:
pool = ThreadPool.new(5)
pool.process do
	sleep 1
	puts 123
end
pool.shutdown
pool.join
add EventLoop implementation

Simple EventLoop which supports timers and deferring work to a thread pool
fix unit test to be directly run from the unit test folder
document PkgConfig.new
remove support for the deprecated rake/rdoctask as it is now an error on Rake >= 10