Introduce preload flag

This is nice for we that like using the CLI.
Don't allow CRuby 2.0.0 to fail on Travis
Merge pull request #297 from jc00ke/master

Add hoe-git
Merge pull request #298 from jc00ke/preload-from-cli

Introduce --preload
Merge pull request #299 from jc00ke/dont-fail-mri-2

Don't allow CRuby 2.0.0 to fail on Travis
Move 1.8s to allow failures (pour one out for our retired comrad)
Fix JRuby restart args, bump 2.2.1
Update History.txt
Fix restart_command in the config
Bump to 2.2.2
Document preload options

Adds some updates to clustered mode docs too
Standardize "block" usage

This commit standardizes on the use of `block` over `blk`. I found the usage of
both in the code.
Merge pull request #301 from catsby/cluster_docs

Document preload options
Merge pull request #302 from catsby/blocks

Standardize "block" usage
Merge branch 'master' of github.com:puma/puma
Add ability to cleanup stale unix sockets
Don't crash when given a non-standard HTTP code
Refactor modes, fix control server to always work
Fix jruby daemonization
Pass Events around more, add Events#on_booted