index: use %USERPROFILE% instead of %HOMEPATH% on Windows
index: use %USERPROFILE% instead of %HOMEPATH% on Windows

%HOMEPATH% is clearly wrong, since it doesn't have the drive letter.
%USERPROFILE% might be better, who knows.

Suggested by mattn.

Fixes #41.

a5b/codesearch,salsifis/codesearch,google/codesearch,junkblocker/codesearch,StephanieMak/codesearch,salsifis/codesearch,StephanieMak/codesearch,google/codesearch,ksmaheshkumar/codesearch,ksmaheshkumar/codesearch,a5b/codesearch,junkblocker/codesearch