Fix an SkCommandLineFlags bug.

Fix an SkCommandLineFlags bug.

Previously I was storing an SkTDArray of const char*,
which fails if the strings go out of scope.

Instead, store an SkTArray of SkString, and copy the
strings, so we do not depend on the strings sticking
around. Using an SkTArray because it is smart enough
to call the destructors, so the copies can be destroyed
on program exit.

BUG=https://code.google.com/p/skia/issues/detail?id=1237

Committed: https://code.google.com/p/skia/source/detail?r=8829

[scroggo, 2013-04-22 22:40:06]

epoger@, this fixes the bug you saw where running without specifying
--ignoreErrorTypes thought a help string from another flag was passed as an
argument to ignoreErrorTypes.

It does not fix the other bug, where the default is not parsed as you expected.

[epoger, 2013-04-23 15:25:37]

LGTM!

[scroggo, 2013-04-23 15:38:15]

Committed patchset #1 manually as r8829 (presubmit successful).