Main/HostDnsService: fix fallout from previous (r99529).

Main/HostDnsService: registry updates for multiple values are not atomic, so wait a bit after registry notification to avoid racing and reading partial update.

Main/HostDnsService: instead of keeping fragile state g/c notifyAll() and just notify proxy directly from setInfo() when info changed.

scm automatic cleanups.

Main/HostDnsService: Tcpip\Parameters\NameServer value is not updated when the list of name servers is statically configured, so don't inspect NameServer and DhcpNameServer directly - instead use DnsQueryConfig(DnsConfigDnsServerList, ...) from DnsAPI.dll

Main/HostDnsService: brush up old Windows code. In general no functional change is intended, but make search list handling follow Windows behavior.

Main/HostDnsService: revert windows code back to r91891. The rewrite in r96327 is wrong. I can't seem to find any paper trail for what was the problem with the original code, but at least it monitors the right place in the registry.

Spell "changed" correctly in an identifier.

Main/HostDnsService: bring back Windows changes of r96331 but with plain std::string in HostDnsInformation and using explicit Unicode API and wchar_t when dealing with registry (we always compile with -DUNICODE, so no need for TCHAR shim). No changes to the original except minor const correctness tweaks.

Main/HostDnsService: revert r96327 and follow-up r96329 and r96331 to revert conversion of HostDnsInformation to Unicode. HostDnsServiceWin.cpp behavioral changes will be redone as a separate commit against old definition of HostDnsInformation. Intervening SafeArray cleanup in r96372 is preserved, hopefully without errors. Please review.

Main: HostDnsMonitor for Windows: remove extra spaces.

Main: HosDnsMonitor for Windows: fix event indexes handling.

Main: DnsMonitorService: step on unicode rails: store network configuration in unicode-compatible containner (std::wstring) (preliminary tested on Linux, Mac and Windows); DnsMonitorService for Windows: reworked in order to subscribe to correct events and filter-out those ones we don't interested in. (Experimantal, needs more testing and review).

Main/HostDnsService: - Generic part could be used with threading on or off: OS which can monitor changes on DNS structures might need this (e.g. Windows, Darwin, Linux) - ResolvConf based (Linux, Solaris, FreeBSD ans Os/2) doesn't use scanf based resovl.conf parsing new Slirp's parser used instead. It's configured to provide strings instead of addresses. (to resolve xtracker/7034c2) - Darwin monitoring code has been refactored. - linux changed to handle cases described in xtracker/7034c3 - Windows monitors changes on register changes.

Main/HostDnsServiceWin: use sizeof() here

Main/HostDnsServiceWin: initlialization of local variables in HostDnsServiceWin::updateInfo(): abDomain, abNameServers, abSearchList.

Main/HostDnsServiceWin.cpp: cast-hummer (char *)BYTE.

Main/HostDnsServiceWin: Monitoring code dont need VirtualBox obj (aParent)

Main/HostDnsServiceWin.cpp: update->updateInfo

Main/HostDnsServiceWin.cpp: Attemp of Windows build fix.

Main/HostDnsService: splits HostDnsService on "singleton" HostDnsMonitor which monitors host changes and share DnsInformation to per HostImpl/VirtualBoxImpl objects HostDnsMonitorProxy. TODO: Win/Darwin parts might burn (not tested) TODO: find good place to call HostDnsMonitor::shutdown() to stop monitoring thread. (ref counting could be used on HostDnsMonitor::addMonitorProxy and HostDnsMonitor::releaseMonitorProxy, but it better to pausing monitoring on no --auto-shutdown launches of VBoxSVC).

Main: Whitespace (including tabs!) and svn:keywords cleanups by scm.

Main: HostDnsServiceWin::init(void) -> HostDnsServiceWin::init(const VirtualBox *aParent) and firing event on update.

Main/DNS: general host specific DNS and Co handling added. Darwin implementation has self-update mechanism, for other hosts it's in todo list.