Merge pull request microsoft#99 from microsoft/master

Update maint/maint-68 for fix for Windows symbols publishing

Cherry-Pick 2 tickets after the ICU 68.2 release (microsoft#63)

This change cherry-picks two tickets from the upstream ICU repo that were merged after the ICU 68.2 release.

- ICU-21427 Don't ignore already checked-in files under "tools/cldr/lib"
- ICU-21118 check that dst and src are not null in uprv_memcpy

The first one I had already done with microsoft#52, so this is mostly just making an update for the comments and to record it in the `changelog.md` file.

The second one was fixed by @erik0686, and prevents undefined behavior in `ultag_parse`.

CP: ICU-21118 check that dst and src are not null in uprv_memcpy
https://unicode-org.atlassian.net/browse/ICU-21118
unicode-org/icu#1489

CP: ICU-21427 Don't ignore already checked-in files under "tools/cldr/lib"
https://unicode-org.atlassian.net/browse/ICU-21427
unicode-org/icu#1500

Update changelog.md for cherry-picked tickets.

Merge pull request microsoft#49 (Update maint/maint-67 to 67.1.0.7)

This updates the maint/maint-67 branch to 67.1.0.7.
(This will be done as a merge commit to keep the history).

Update the changelog.md and version number to `64.2.0.3`, in order to…

… prepare for a new release. (microsoft#47)

Merge pull request microsoft#36 (Update maint/maint-67)

Update maint/maint-67 to pick up fix for Nuget code-sign config file

Merge pull request microsoft#12: Update maint-67 for the Taiwan calen…

…dar changes.

This change merges the Taiwan calendar changes (PR microsoft#8) and the runtime Nuget changes (PR microsoft#9)
into the maint/maint-67 branch. The version number has been bumped to 67.1.0.2 for these changes.

Note: To preserve the history of the commits, this change will need to be merged as a "merge commit", rather than the usual squash merge approach.

Update the changelog and bump the version number to 64.2.0.2 for the …

…Taiwan calendar changes. (microsoft#14)

This PR updates the `changelog.md` file for the Taiwan calendar changes, and bumps the MS-ICU version number to `64.2.0.2`, in order to prepare for a new release.

Fix another typo in the Nuget targets file. (microsoft#7)

Add changelog.md file.