* Use the unicode version of the System and UserInfo plugins to fix
   non-english languages in the Windows installer.
 * Update the installer to use the inetc plugin so that https downloads will
   work.  This became necessary because Sourceforge now redirects http to
   https.
 * Standardize everything in pidgin/win32/winpidgin.c to use `wprintf`.

Compiled and ran on windows 10.