DO NOT MERGE: Cherry-pick: ICU-20659 Fix DTD link in XML data files

When upstream switched from svn to git they did not update dtd cache
links which led to having corrupted data instead of cache data. This
prevented ./tools/updateicudata.py script from working correctly and the
build was failing.

This has been fixed in the following upstream commit:
https://github.com/unicode-org/icu/commit/d56f291178bd63fae22c4f528f31fd5d9610b4fb

- http://www.unicode.org/repos/cldr/trunk/common/dtd/ldml.dtd returns
  HTTP 302 error and redirects to an html page, not a dtd content
  apparently.
- Clone the dtd files from CLDR release-35-1
  https://raw.githubusercontent.com/unicode-org/cldr/release-35-1/common/dtd/ldml.dtd

Test: n/a
Bug: 141108188
Merged-In: I6c2a137e16ab63b4cd006c6db9b2c60f1b20d8f9
Change-Id: I6c2a137e16ab63b4cd006c6db9b2c60f1b20d8f9
(cherry picked from commit ddd011ed17be7e3caf26adf4bab1856ffbcf5ba3)
(cherry picked from commit 02436bf5fe485b1e2c57951e7eb1be80856e627b)
36 files changed