msvc 2010, 2008 no longer supported,

[gfgtdf]

wesnoth no longer supports msvc 2010 and 2008 so the asiciated external packages/branches can be removed.

[aquileia]

Wesnoth 1.13 may no longer support older versions of Visual Studio, but as long as 1.12 is the current stable, VC9 and VC10 play their role.

[GregoryLundberg]

Bump