Fix bad merge with crew

Move patch-related code into its own module.

Teach import to understand git diff extensions. Vanilla patch chokes on git patches that include files that are copied or renamed, then modified. So this code detects that case and rewrites the patch if necessary.

update copyrights.

merge.

Fix some bugs introduced during the manifest refactoring

Fix "hg qnew -f foo" without -m The refresh method assumes it has a string.

merge with mpm.

import: get lock and wlock one time this makes import of many patches 6x faster in kernel repo.

Adjusted documentation for hgrc's "[smtp] host" for change in 9f745d3675d4.