Tidy up Console, fix ConsoleTest

- Use a more specific exception type. The use of
  IOException led me to believe that the constructor
  was performing i/o ops on the underlying file
  descriptors. (They were not.)

- Delete a test that asserted that System.console() was
  always non-null. It will be non-null only for command
  line apps (tests run from vogar), and not for
  "regular" android apps (tests run from CTS) because
  stdin / stdout will not be TTY devices regular apps.

bug: 12490236
Change-Id: I8c1e37bcb21de5862dc8ea198852995a020437a7
Partially fix GregorianCalendarTest.

ICU4C data (see icu4c/data/misc/supplementalData.txt)
as well as the RI agree that the minimum number of days
in the first week of the year should be 1 in canada.

(I'm not a 100% convinced that this is correct, the
canadian standards board claims to have implemented
ISO 8601, which requires a 4 day minimum. However, that
site links to several documents such as CSA Z234.5 that
are not publicly accessible).

Change-Id: I1d62c7f94d5f059b6ba2ad60bcf8434cdea0d9ce
Fix GregorianCalendarTest#test_addII.

We're going through the trouble of accounting for
DST changes in GregorianCalendar.add(int, int) (as per
the spec), so adjust our tests to agree.

bug: 12778197
Change-Id: Ie98cc11c2a2f7f6d9c7be8d725960552309f4f5d
Merge "Partially fix GregorianCalendarTest."
Merge "Fix GregorianCalendarTest#test_addII."
Merge "Tidy up Console, fix ConsoleTest"
Merge branch 'master' of https://android.googlesource.com/platform/libcore into HEAD