64-bit windows agent, check_mk_agent_x64.exe, Visual Studio 2010 configuration
* agents/windows/check_mk_agent.cc
  changes for vc++
* agents/windows/.gitignore
  ignore visual studio cruft
* agents/windows/check_mk_agent.sln
* agents/windows/check_mk_agent.vcxproj
* agents/windows/check_mk_agent_x64.exe
* agents/windows/dirent.c
* agents/windows/dirent.h
Windows workaround for missing sys/time.h gettimeofday()
Added:
 * agents/windows/gettimeofday.h
Modified:
 * agents/windows/check_mk_agent.cc
 * agents/windows/check_mk_agent.vcxproj