Minor documentation/haddock fixes
Add truncated exponential distribution
Remove unused Show constraints

They were used during debugging and were not removed
Add workaround for GHC bug #8072

GHC-7.6 have bug (#8072) which results in calculation of wrongs
number of buckets in function `uniformRange'. Consequently unformR
generates values in wrong range.

Bug only affects 32-bit systems and Int/Word data types. Word32
works just fine. So we set Word32 as unsigned counterpart for Int
and Word on 32-bit systems. It's done only for GHC-7.6 because
other versions are unaffected by the bug and we expect that GHC may
optimise code which uses Word better.

Fixes #25
Merge
Merge
Fix various English language issues
Bump version to 0.13.0.0
Added tag 0.13.0.0 for changeset c8ef9b6ed671
Merge pull request #23 from DougBurke/master

Minor documentation fixes
createSystemRandom
Merge branch 'master' of https://github.com/snoyberg/mwc-random