patchbomb: quoted-printable encode overly long lines RfC2822 mandates a line length limit of 998 byte + CRLF. Python mail tools break lines at 990 byte. To prevent that, we quoted-printable encode overly long lines.

patchbomb: fix quotes in help string

Windows: improve performance via buffered I/O The posixfile_nt code hits the win32 file API directly, which essentially amounts to performing a system call for every read and write. This is slow. We add a C extension that lets us use a Python file object instead, but preserve our desired POSIX-like semantics (the ability to rename or delete a file that is being accessed). If the C extension is not available (e.g. in a VPS environment without a compiler), we fall back to the posixfile_nt code.