[win32] use MSBuild.exe or devenv.com (if available) in BuildSetup.bat to get verbose console output
[win32] cosmetic in BuildSetup.bat
[jenkins] - do the mingw build in a backgroundthread and echo "." on the foreground thread for giving continuous output to the jenkins slave - should fix the disconnect issue on win32 slave
Add #include guards for HAS_PYTHON

This fixes compile of Addon.cpp and Weather.cpp if HAS_PYTHON is not defined
Remove Python dialogs when compiling without Python

cherry-picked from https://github.com/plexinc/plex-home-theater-public/commit/f76df3e72
Retain type safety by using const_cast instead of C-style cast
Merge pull request #2868 from Montellese/win32_msbuild

[win32] make BuildSetup.bat et. al. more robust for jenkins builds