Fixing typos
Fix typo
First pass of functions to convert between NominalDiffTime and
Delay/TimeInterval
Various tweaks to get the build working once again with ghc-7.4.x

Conditional dependencies (re)introduced, plus some conditional imports
and relaxing one of our test timeouts, since it seems to regularly
fail on CI.
Add build-status icon
Update README.md
Merge remote-tracking branch 'root/development' into difftime

Conflicts:
	src/Control/Distributed/Process/Platform/Time.hs