Fix Dropwizard healthcheck.

The resource should only return unhealthy if the node is leading and
the scheduler is not running. For a standby node (not leading), the
scheduler can (and must!) be down.

Turns out no one seems to use that. :-)
Merge pull request #359 from hgschmie/healthcheck-fix

Fix Dropwizard healthcheck.
Expose SingularityTaskId to the executor through environment variables
De-crapify setting of environment variables
Take Object for value and toString it for convenience
[maven-release-plugin] prepare release Singularity-0.4.0
[maven-release-plugin] prepare for next development iteration
updates to log fetcher
Update README.md
only grep if argument provided, fix task ids for deploys
Factor out the Scheduler lock.

Inject the scheduler lock object everywhere it is needed. Also break
up the "parent injection" pattern which is not needed with DI for the
poller classes that hang off SingularityLeaderOnlyPoller.
only grep relevant logs, better messaging
Update Mesos to 0.21.0 and add option for pure java API code.

Add a configuration flag that allows switching between using the native library from Mesos and the
jesos pure java API. Default is to still use native code.

This also updates the mesos version to 0.21.0.
refactor into python package
default destination to ~/.logfetch
easier install
update defaults
Replace SINGULARITY_DEPLOY_ID with TASK_DEPLOY_ID for similarity to TASK_REQUEST_ID
Merge pull request #351 from hgschmie/jesos-option

Update Mesos to 0.21.0 and add option for pure java API code.
Merge pull request #346 from hgschmie/factor-out-lock

Factor out the Scheduler lock.