Merge pull request #68 from florianleibert/master

Pulling out the interface for HttpServerDispatch
Make test discovery errors fatal.

Otherwise test may silently-ish not run.
Merge pull request #69 from benjyw/master

Make test discovery errors fatal.
Bugfix in IvyResolve.

Consider a set of targets A, a superset A', and some other set B.

Building A' resolves for A', and then building B resolves for B. If you
then try to run something from A, nothing in it is invalid, and previously
this meant that we wouldn't re-resolve, and instead try to symlink to the
classpath file from a previous compile of A. Except that there isn't one,
so the classpath would remain that of B, and the run would file with
ClassNotFound errors.
Merge pull request #70 from benjyw/master

Bugfix in IvyResolve.
Reworking pants invalidation.

This simplifies the code by having all invalidation done by the
same mechanism, namely changes to the cache_key. For example,
to invalidate dependents we used to manually go through a target's
dependents and invalidate them by force. Now we just add in
each target's dependencies when we compute its cache keys.

This ends up unifying a bunch of special cases, thus making the
code more succinct. It's also more correct wrt artifact caching:

Now two artifacts build with the same sources but different upstream
deps will have different cache keys, as they should.
Let zinc emit the scalac depfile instead of the plugin.
Let zinc emit the scalac depfile instead of the plugin.
Bugfix in pants target ordering.
Merge pull request #74 from florianleibert/master

Changing import order in HttpModule
Another bugfix.
Changing the import order for checkstyle, adding publish support
Revert "Changing the import order for checkstyle, adding publish support"

This reverts commit 0960adef5cd0177b231edfac820af7ef36bc1e94.
Changing the import order
Fix code review comment.
Merge pull request #71 from benjyw/master

Reworking Pants invalidation logic.
Initial vut at travis-ci integration.
Let travis handle python 2.6 and get the jdk via apt.
Try a different openjdk package name.
Set language to python to correct python environment for pants.