Cosmetic changes (spelling, grammar) and fix an annoyance.

Cosmetic changes (spelling, grammar) and fix an annoyance.

* "x can't contain y because of z" sounds like it means
  "but x might contain y because of a reason OTHER than z"
* wrong reference to Open Group specification
* always interpret the specified "--output" as a directory

BUG=none

Committed: https://crrev.com/225bf680e62b2e6d51d2dc108c9098c96138093f
Cr-Commit-Position: refs/heads/master@{#316139}

[dougk, 2015-02-12 21:06:24]

dougk@chromium.org changed reviewers:
+ brettw@chromium.org, davidben@chromium.org

[brettw, 2015-02-12 22:51:43]

lgtm

[davidben, 2015-02-12 22:52:54]

net lgtm

[dougk, 2015-02-13 00:41:40]

The CQ bit was checked by dougk@chromium.org

[commit-bot: I haz the power, 2015-02-13 00:43:07]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/922833002/1

[commit-bot: I haz the power, 2015-02-13 02:48:03]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-02-13 02:48:40]

Patchset 1 (id:??) landed as
https://crrev.com/225bf680e62b2e6d51d2dc108c9098c96138093f
Cr-Commit-Position: refs/heads/master@{#316139}