Merge pull request #259 from liyang/master

clean up travis/cabal-apt-install script
Added Control.Lens.Internal.Exception. Added handled, handled_, IsHandler(..) to Control.Exception.Lens
CHANGELOG entry for Control.Exception.Lens changes
Removed `Show` constraint from `base`.
more doctests
more Traversal doctests
Review doctests and laws
Added a `Handler` and `catches` notion to `Control.Monad.Error.Lens`. Refactored `Handler` support.
Revised 3.8.2 CHANGELOG
Removed redundant import
fixed linking
better escaping in haddocks
haddock linking
Added missing haddock |
haddocks: linking, typos in Exception
haddocks: '-- |'-ed internals, 'Handling' -> @Handling@
Added strippingSuffix
Merge branch 'master' of github.com:ekmett/lens
Update AUTHORS.markdown

Resolve the Markdown conflict in `nand`

Fix danr's email
Merge pull request #260 from danr/patch-1

Update AUTHORS.markdown