Allow RefCountedPtr to be assigned and copied from compatible RefCountedPtr.
Do not copy/assign reference counter.
Atomic reference counter.
Delete RefCounted copy/move constructors and assignment operators. Change the only place relying on it.
Used std::atomic<int> and explicit m_refCount(0) to initialise.
Visual Studio 2012 doesn't support the `= delete` syntax so simply made copy constructors and assignment operators private with no implementation. VS2013 does seem to support it but we still need to support VS2012.
Merge branch 'lwho/ref_counted_ptr'
Fixup non-breaking vs2012 UI project files.
Added a landing position offset value and method.
Populate it by looking for `tag_landing` in a ship model.
Use the new ship landing position offset value.
Cleanup passing the ship pointer around to where it's no longer used and assert that it's valid where it is.
Defunct stuff.
New starting ships
Replace the amphiesma high detail model with one which has the tag_landing built into it.
Merge remote-tracking branch 'nozmajner/start_ships'
Merge remote-tracking branch 'fluffyfreak/tag_landing_issue_2656'
Merge pull request #40 from pioneerspacesim/master

Sync to master