Updated dependencies and types for Haskell llvm bindings v3.3.8.1.
Modifying the System.getEnv function to return IO (Maybe String)

For edwinb/Idris-dev#331 , allowing a segfault on returning a
null pointer string is very bad. This requires that either the
value is present or it returns Nothing.
Merge pull request #488 from gabemc/master

Fixing a typo in the --help usage screen.
Merge pull request #489 from gabemc/issue/331

Issue #331: Modifying the System.getEnv function to return IO (Maybe String)
Merge pull request #485 from lambdadomain/master

Updated dependencies and types for Haskell llvm bindings v3.3.8.1.
Fix coverage checking for functions matching constants

Generates an example case for a constant which isn't matched explicitly.
This should be sufficient to ensure that any case which isn't given
explicitly is also handled.