Move version to its own module so that version can be defined in one
place but setup.py does not need to import crochet to get it.
Instead setup.py just execs the version module to get the version.
Added simple test to catch install issues like #18 in future
Merge pull request #20 from cscutcher/issue-18

Fix issue #18: Allow setup.py to work without required twisted to be preinstalled.
Post-merge cleanups: punctuation, and use Travis-CI to test setup.py can be run without dependencies installed.
Note setup.py fix in README.
Remove side-effects on import of Crochet.

Fixes #19.
Move interrupting of blocking EventualResult.wait() calls to earlier in reactor shutdown.

Fixes #17.
Add section on use cases to the documentation.

Fixes #16.
Change version to 1.0.0.
Merge tag '1.0.0' into deb_precise

v1.0.0
package v1.0.0