Details: Moving files so that the local layout corresponds to the layout pushed by make install.
Adjust Make target, modify the resource path of the loader to find the resources in the
right place. All pathes are still looked up relative to binaryPath(), libs are found via
relative rpath.

Task:     - none
RevBy:    - Andre

there anymore

Since it's checkable now, "Show Sidebar" is more suitable. Also changed
the interface a bit to allow more than just toggling.

replace ExtensionSystem::PluginManager::instance()->getObject<Core::ICore>() by Core::ICore::instance()

It was getting a bit cluttered without any grouping of the different
actions. Also, the collapse and expand actions have been added, mainly
for discoverability.

on gdb startup)

Now the box will grow larger when files with long filenames are opened.

forward declaration is sufficient.

Also made sure the glossary terms aren't wrapped, since that didn't look
very nice.

For the documentation about the dependencies the screenshots should be
updated again.

Dependencies between projects can now be edited in the Projects mode.
You can simply check for each project the projects that it depends on,
and they will be built first. A message box pops up when you try to
create a circular dependency.

Could use some testing.

Details:  Works.