Drop jar from the coprocessor schema.

Dealing with filesystem paths across use cases (production deployment,
local testing) is just too weird.  Instead we'll require individual
tools to collect those paths another way if they need them.
Extract some "mixin" shared contexts from the hbase shared context.

It was getting unweildy.  Also make some methods private & drop use of
(now no-op) :test_classpath.

The hbase/loggers spec helper loads the hbase environment.
HBaseEnvironment.configuration gets you the effective HBase config.
askari/schema/application aliases the v0 application class.

This protects disinterested code from versioning changes.  A schema
client still needs to be aware of format versioning, but they should
examine the `format` attribute of the application instance to do so.
Visitation implements half of the visitor pattern.

Tool (and mixers) will implement the other half.
A tool can create and perform plans (Enumerables) of Actions.

An action is a proc with a descripton.
Extract tool_examples.rb
Have a creator tool and a create command.

It runs the creator tool.  If -p or --pretend is passed, it prints the
plan.  Otherwise it runs it.

Since jar paths aren't in the schema anymore, they must be passed
explicitly.  The -j option accomplishes this.  Relative (or just
absolute, schema-less) filesystem paths get resolved against
`file:${CWD}` to make absolute file: paths.

The creator tool deals with just about all of the HBase table and
family configuration options.  It can register coprocessors.