[15] RFR: 8174270: Consolidate ICU sources in one location

[naoto.sato at oracle.com]

Hi,

Please review the fix to the following issue:

https://bugs.openjdk.java.net/browse/JDK-8174270

The proposed changeset is located at:

https://cr.openjdk.java.net/~naoto/8174270/webrev.00/

Although the number of modified files are huge, the change is simply 
moving the scattered ICU sources in various locations under 
jdk.internal.icu package, keeping the original ICU's source tree structure.

Naoto