Merged from trunk 5113:5119

Merged from trunk 5113:5119

For bug #142993, make sure that chown and chgrp calls preserve S_ISUID
and S_ISGID mode bits.

Fix apply_permissions logic for cases where mode is unspecified.

Fix bit mask support when preserving S_ISUID and S_ISGID in
apply_permissions.
Really fix bit mask support when preserving S_ISUID and S_ISGID in
apply_permissions.

Fix a KeyError in emerge --info <pkg> when there is no matching ebuild
in the tree.  Thanks to Bo ?\195?\152rsted Andresen
<bo.andresen@zlin.dk> for reporting.

Use portage_data.lchown for compatibility.

svn path=/main/branches/prefix/; revision=5120