ticket:10268: Initial check in of C++ Measurement API.

git-svn-id: http://source.icu-project.org/repos/icu/icu/branches/tkeep@34842 251d0590-4201-4cf1-90de-194747b24ca1
ticket:10268: Fixed getAvailable() to take just a MeasureUnit *

git-svn-id: http://source.icu-project.org/repos/icu/icu/branches/tkeep@34847 251d0590-4201-4cf1-90de-194747b24ca1
ticket:10268: Added MeasureFormatTest

git-svn-id: http://source.icu-project.org/repos/icu/icu/branches/tkeep@34848 251d0590-4201-4cf1-90de-194747b24ca1
ticket:10268: Alphabetize types and subTypes in MeasureUnit.

git-svn-id: http://source.icu-project.org/repos/icu/icu/branches/tkeep@34849 251d0590-4201-4cf1-90de-194747b24ca1
ticket:10268: Merge from trunk r34700 - r34849

git-svn-id: http://source.icu-project.org/repos/icu/icu/branches/tkeep@34850 251d0590-4201-4cf1-90de-194747b24ca1