Merged from trunk 5659:5673

Merged from trunk 5659:5673

fix minor syntax issues with locking (WarnerBro)

Enable repoman to commit a Manifest alone instead of bailing out with
"Didn't find any changed files".

ferringb pointed out this portroot parameter, ended up not using it, try
an os.path.exists to save a very common (and slow) except on missing
repo_name files for overlays, use a dict to facility a nicer regex
comparison loop for news restrictions. (WarnerBro)

document FEATURES=sesandbox #161985 (SpankMan)

make.conf is not a manual so only list common FEATURES #161985 (SpankMan)

dirty dirty lies (WarnerBro)

Make repoman commit removals together with the other changes (instead of
with the final Manifest commit).

For consistency, just use os.environ.

Fix broken commitmessagefile handling.

Replace mktemp with mkstemp since the former is deprecated for security
reasons.

Various glep 42 fixes, fix up the portageq calls to fail properly,
rewrite the news checking code to check news for all repos with a name.
(WarnerBro)

fix a few typos in tests (WarnerBro)

If repo/profiles/news doesn't exist, return 0 updates (WarnerBro)

switch news timestamp and unread/read storage to '/var/lib/gentoo' like
the GLEP states. (WarnerBro)
(Prefix adjusted)

svn path=/main/branches/prefix/; revision=5726