test-casefolding: fix wrong case on hfs on linux
on linux hfs keeps the old case of the file stored
force it by renameing to another name and back
hghave: check for case insensitive filesystem in current dir
check was done on TEMP
use 'x in dict' instead of 'dict.has_key(x)'
"in" is faster, and has_key will be removed in py3k
churn:
issue833 was reintroduced in
9bc46d069a76, correct it and add a test