Minor code cleanup in clojure.test.check

Signed-off-by: Reid Draper <reiddraper@gmail.com>
Use `core` for `clojure.core` in generators namespace

This keeps this noise in the code due to naming collisions down.

Signed-off-by: Reid Draper <reiddraper@gmail.com>
Don't use flatten

The recursive nature of flatten is not needed here, and it precludes
having arguments to quick-check that have sequential literals.

If clojure.core had mapply this wouldn't be so awkward.

Signed-off-by: Reid Draper <reiddraper@gmail.com>
Use a Generator record rather than a simple map. Refs #19

Signed-off-by: Reid Draper <reiddraper@gmail.com>
Add generator? test function

This will be useful in the future for building helpful errors messages
and function-argument preconditions.
Merge branch 'feature/generators-as-records'
Merge branch 'feature/code-cleanup-fredericks'
Remove outdated comments
Add Clojure/West video link to README
Merge branch 'master' into fork

Conflicts:
	src/main/clojure/clojure/test/check.clj
	src/main/clojure/clojure/test/check/generators.clj