Update sources to 5.0.6

[dmik]

A fresh bunch of patches by valorous is made against revision 58105 of the OSE SVN (​https://www.virtualbox.org/changeset/58105/vbox, made on 05.10.2015). The closest official release of VirtualBox is 5.0.6 (released on 02.10.2015).

[dmik]

Note that I found out (thanks to Knut) that the official release of 5.0.0 and 5.0.2 from trunk (mirrored in the OSE repository) was an exception. Usually the upstream VirtualBox team releases new versions from private branches not available in the OSE repository. For this reason, there is no state in this repository that would match official releases (and BTW this is the reason why it doesn't carry any version number changes or changeling updates — it's stuck with an internal version number of 5.0.51).

They, however, release a source tarball per each official release of VirtualBox here: ​http://download.virtualbox.org/virtualbox/. So we will switch to taking new upstream releases from these tarballs (as we already do for many other projects) instead of attempting to take them from OSE SVN. I will switch to this scheme right now.

Note that this also implies the following:

• The external reference to kBuild will disappear from the vendor tree including the kBuild directory itself (this had to be done anyway as we already did that on trunk, see r6).
• The kStuff external reference to some kStuff stuff (stored as src/libs/kStuff/kStuff) will also go away because tarballs obviously don't support external references. They simply include a copy of kBuild (which we will drop because we maintain it on our own) and a copy of kStuff (which we will use both in vendor and in trunk, to get this not really necessary external dependency and to keep things simple).

If we ever need to take something hot from OSE SVN (like some hot fix or such) it will still be possible of course. The above mostly applies to the vendor tree.

[dmik]

One more clarification of why it's preferable to stick with official releases rather than OSE. OSE exposes only the trunk line of the whole VirtualBox development. The trunk IIRC is used by the dev as the main development branch. Releases are done from branches which may differ from the trunk: contain important fixes and may be even features not available on the trunk (at least at the time of the release). Or they may use any other strategy, it doesn't really matter. What matters is that the tarball is (at least, supposed to be) an exact copy of the release including the same level of stability and quality control Oracle meant to address to it. While the stability and quality of the trunk is unknown to us. So using tarballs gives us what Oracle does to their releases (in terms of quality control) for free.

[dmik]

Task done; r14 is trunk with 5.0.6 merged in (and there is now source:/vendor/5.0.6 for future reference). Valorous, please svn up to stay up-to-date.