Update to longtail 4.0 and bump version to 0.5

Update longtail to 0.3.8 and bump version to 0.0.4

Merge pull request #12 from Golle/feature/ratelimitprogressapi

Add implementation for Longtail_CreateRateLimitedProgress

update longtail to 0.3.7 and add the new API VersionIndex.Merge()

version 0.0.1

rc 3

Merge pull request #8 from Golle/release/0.0.1-rc2

Release 0.0.1-rc2