[Python] Adds keyboard to dialog class, using all of Dialog().numeric() methods.

This does not eliminate xbmc.Keyboard() or Dialog().numeric. Those could be depreciated.
[win32] ping ; avoid log when no reply
Merge pull request #2629 from nuka1195/Branch_Python_Keyboard_to_Dialog

[Python] Adds keyboard to dialog class, using all of Dialog().numeric() methods.
Merge pull request #2862 from t4-ravenbird/ping-errmsg

[win32] ping ; avoid log when no reply
[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
[Pictures/Slideshow] Treat gifs as videos in the picture area.