Release of 1.4.1

- 6920be44d859aa68f6515c7de4ff00489fda9190: Merge pull request #716 from mattrjacobs/unfinal-execute-and-queue
- a899696b1a5d97e8f290f2e225080515a4814d61: Make HystrixCommand.execute()/queue() and AbstractCommand.observe()/toObservable() nonfinal
- 05ea381e75b806ad6b86b996d735f8c70a0c6926: Update README.md
- 5991989e4c829fabc0642c1484144da9a7f5ebcf: Merge pull request #710 from wblakecaldwell/patch-1
- 6c14c79a53f4f455990ff964731840b991eb38ff: This fixes #709: JS error: "isNan is not defined"
- 5d1874b3678c454d7ac36cef702a13bf6b4638ce: Merge pull request #706 from mattrjacobs/fix-javadoc-generation
- 17b2cdf350a5b76023a98589d1fd072e8f164289: Fix Javadoc generation and some Javadoc warnings
- 1377edd1b40d2cd44cf2d43ff259eefe3d5ae3eb: Update CHANGELOG.md
