API|Uri: Added new Uri constructor Uri_NewWithPath3

A default scheme is set for the new Uri before then parsing a cstring
representation of a Uri, bypassing the resource class mechanism.

This provides a convenient method of constructing a Uri with a default
scheme that may be overridden with the cstring argument.
ACS|Cleanup: Use Uri_NewWithPath3
libcommon: Provide a Reader/Writer to all save state (de)serialization routines
Refactor|ACS: Implement ACScript (de)serialization in C++ with Reader/Writer

Also, ACScript_Thinker() now calls the C++ method ACScript::runTick()
Refactor|libcommon: Switched more libcommon source files to C++
Refactor|libhexen: Switched p_pillar.c and p_waggle.c to C++
Refactor|libcommon: Switched p_door.c to C++
Fixed|UI|Log: Update filter after reseting to defaults

IssueID #1722
OS X|Fixed|libgui: Use Qt fonts in the 10.6 Snow Leopard build

The Core Graphics API is not available in 10.6.
UI|Task Bar: Show the MP menu when connected to a server

The Multiplayer menu has its own class.

The task bar’s layout is now updated using a SequentialLayout
which makes it easier to manage dynamically changing content.
Refactor: Switched each games' p_lights.c to C++
Refactor|libcommon: Implement thinker (de)serialization in C++, with Reader/Writer

Todo: mobj_t and Hexen's polyevent_t
Merge branch 'master' of ssh://github.com/skyjake/Doomsday-Engine
libdeng2|Log: Print log entry timestamp using seconds since start

More compact and informative than omitting the hour.
Fixed|Client|All Games: Busy mode transition when map changes in netgame
Refactor|libcommon: Switched p_xgsave.c to C++
Refactor|ACS|Hexen: Implement ACS state (de)serialization in C++, with Reader/Writer
Refactor|Hexen: Implement sound sequence (de)serialization with Reader/Writer
Refactor|XG|libcommon: Implement XG plane-mover (de)serialization in C++, with Reader/Writer
Merge branch 'master' of github.com:skyjake/Doomsday-Engine