o Recursive cp.
o Fix for incorrect path resolving on remote drives.
o Fixed missing cleans.
o Fixed appending with recursive reference to the target variable.
o Fixed prepending /w expansion (was appending instead of prepending).
o Added CLEAN property to all target types.
o New attribute USES for including units (for (f)lex, bison, qt, and other complicated stuff).
o New $(breakpoint ) function for debugging kmk.
o Added DragonFly BSD to env.sh and the os list.
