util: add overwriteChainableMethod utility (for #215)
util: code style fix
util: store chainable behavior in a __methods object on ctx
return error on throw method to chain on error properties, possibly different from message
Merge pull request #219 from demands/overwrite_chainable

Add overwriteChainableMethod utility
Add `has` to language chains
Merge pull request #224 from vbardales/master

Return error on throw method to chain on error properties
support `{a:1,b:2}.should.include({a:1})`
add failing test case
handle negation correctly
Update Copyright notices to 2014
Merge pull request #231 from duncanbeevers/update_copyright_year

Update Copyright notices to 2014
Avoid error instantiation if possible on assert.throws

Given an error constructor as function, try to get the error name from
its prototype or itself before relying on the old behaviour.

Closes #220

Replaces [the old pull](https://github.com/chaijs/chai/pull/221) to avoid
useless commits.
Merge pull request #226 from duncanbeevers/add_has

Add `has` to language chains
Remove coveralls
Remove jscoverage
Test coverage with istanbul
Remove the not longer needed lcov reporter
Remove lib-cov from test-travisci dependents
Add coverage to npmignore