ticket:10461: Make sure to pass locale objects instead of char * when getting NumberFormat, PluralFormat object.

git-svn-id: http://source.icu-project.org/repos/icu/icu/branches/tkeep@35104 251d0590-4201-4cf1-90de-194747b24ca1
ticket:10461: Implement option A where cached MeasureFormatData holds onto shared references to big, expensive objects like NumberFormat and PluralRules.

git-svn-id: http://source.icu-project.org/repos/icu/icu/branches/tkeep@35105 251d0590-4201-4cf1-90de-194747b24ca1
ticket:10461: Improve documentation and variable names.

git-svn-id: http://source.icu-project.org/repos/icu/icu/branches/tkeep@35109 251d0590-4201-4cf1-90de-194747b24ca1
ticket:10461: Make RelativeDateTimeFormatter use cached, shared Numberformat and plural rules.

git-svn-id: http://source.icu-project.org/repos/icu/icu/branches/tkeep@35110 251d0590-4201-4cf1-90de-194747b24ca1
ticket:10461: Introduce introduce cache shared object in both MeasureFormat and RelativeDateTimeFormatter.

git-svn-id: http://source.icu-project.org/repos/icu/icu/branches/tkeep@35111 251d0590-4201-4cf1-90de-194747b24ca1