test-clone-failure: reenable perm to allow deletion

patch: create file even if source is not /dev/null as long as the first hunk is -0,0 and the source and destination have the same name. Matt found a patch like this, and /usr/bin/patch accepts it.

Merge with crew

Fix failing darcs test

Merge with mpm

Merge backout of 26fa0e31011d

Backed out changeset 26fa0e31011d. On OS X, it broke test-issue322, test-issue660, test-permissions, test-symlink-addremove, and test-walk.

mercurial.ini: provide more useful info * Add warning about not editing the site-wide file on Vista * More detail about where to create user Mercurial.ini * Provide examples for ssh tools * List extensions, all disabled * add [patch] section, for fixing patch behavior when using win32text * example [extdiff] section, all disabled * example [diff] section, all disabled

churn: correct output when run in subdirectories

i18n: move unrelated line out of try-except block