devel/icu: move to new home

http://blog.unicode.org/2018/07/icu-moves-to-github-and-jira.html

$ diff -r icu4c-62_1/ icu-release-62-1/icu4c/
Only in icu4c-62_1: .gitignore
Only in icu4c-62_1/as_is: bomlist.txt
Only in icu-release-62-1/icu4c/source/data: brkitr
Only in icu-release-62-1/icu4c/source/data: coll
Only in icu-release-62-1/icu4c/source/data: curr
Only in icu4c-62_1/source/data/in: icudt62l.dat
Only in icu-release-62-1/icu4c/source/data: lang
Only in icu-release-62-1/icu4c/source/data: locales
Only in icu-release-62-1/icu4c/source/data: mappings
Only in icu-release-62-1/icu4c/source/data/misc: currencyNumericCodes.txt
Only in icu-release-62-1/icu4c/source/data/misc: dayPeriods.txt
Only in icu-release-62-1/icu4c/source/data/misc: genderList.txt
Only in icu-release-62-1/icu4c/source/data/misc: icustd.txt
Only in icu-release-62-1/icu4c/source/data/misc: icuver.txt
Only in icu-release-62-1/icu4c/source/data/misc: keyTypeData.txt
Only in icu-release-62-1/icu4c/source/data/misc: likelySubtags.txt
Only in icu-release-62-1/icu4c/source/data/misc: metaZones.txt
Only in icu-release-62-1/icu4c/source/data/misc: metadata.txt
Only in icu-release-62-1/icu4c/source/data/misc: miscfiles.mk
Only in icu-release-62-1/icu4c/source/data/misc: numberingSystems.txt
Only in icu-release-62-1/icu4c/source/data/misc: plurals.txt
Only in icu-release-62-1/icu4c/source/data/misc: supplementalData.txt
Only in icu-release-62-1/icu4c/source/data/misc: timezoneTypes.txt
Only in icu-release-62-1/icu4c/source/data/misc: windowsZones.txt
Only in icu-release-62-1/icu4c/source/data/misc: zoneinfo64.txt
Only in icu-release-62-1/icu4c/source/data: rbnf
Only in icu-release-62-1/icu4c/source/data: region
Only in icu-release-62-1/icu4c/source/data: translit
Only in icu-release-62-1/icu4c/source/data: unit
Only in icu-release-62-1/icu4c/source/data: xml
Only in icu-release-62-1/icu4c/source/data: zone