Copy ICU4C 56 RC from icu-project.org to aosp/icu56.

These files were exported from the ICU Subversion repository by running
the following command:

svn export \
  http://source.icu-project.org/repos/icu/icu/tags/release-56-rc/ icu4c

(Previously, only the subdirectory "source" and the files in the root
directory were exported to Android, as the other subdirectories only
contain files that are not relevant when using ICU4C in Android. Now
these are included anyway, to simplify the export process.)

Change-Id: I5457d90c5b3ec6d3ef966e2921fe7d2bb75d76cd
3497 files changed