bitbake-dev: Refactor the environment variable handling.

Do not clear the environment when saving the environment to the data store.
Instead clear this once the cooker has forked. This ensures that the UI
operates in a filtered (but not empty) environment.

git-svn-id: https://svn.o-hand.com/repos/poky/trunk@5526 311d38ba-8fff-0310-9ca6-ca027cbcb966

bitbake-dev/lib/bb/data.py

@@ -331,8 +331,6 @@ def inheritFromOS(d):
             setVar(s, os.environ[s], d)
         except TypeError:
             pass
-        os.unsetenv(s)
-        del os.environ[s]
 
 def emit_var(var, o=sys.__stdout__, d = init(), all=False):
     """Emit a variable to be sourced by a shell."""