Release of 1.5.1

- 19dd71ea6bbaac642462ae50df5ed69008bfb846: Merge pull request #1118 from mattrjacobs/revert-user-thread-latency-removal
- a8c3276449efb44fcfa7d7deced8e9ba2a5107e4: Revert "Deprecate methods to retrieve userThreadLatency, and remove it from standard metrics being published"
- 62c39e17aca43fcace3aee3513d6afa772137d7c: Merge pull request #1116 from exys666/fix-underscore-url
- 1dcd0fddba399bb203ab9a8564a2385917e36df7: Merge pull request #1115 from nyango/nyango-patch-1
- d4ce53cb59c223f0e802aefc6698272a056fcf3e: Fix underscore.js url
- 17632fe0676bc392e5e9ba4f9cd4ed7f172d97db: Rename LICENSE in order to be referred to README
