[maven-release-plugin] prepare for next development iteration
minor change
Add synchronized keyword for Date related method to avoid conflict in multi-thread condition.
Merge pull request #29 from MengZhang/develop

Develop pull request from Meng
Merge branch 'develop' of github.com:agmip/agmip-common-functions.git
[maven-release-plugin] prepare release agmip-common-functions-1.3.4
Merge branch 'release-1.3.4' (early part)