Update to jnr-posix 2.4.0 to round-up all the enebo changes.
Bump for 1.7.1
Update install4j to know about gems subdir
Fixed implicitly creating a vertex if it is absent while removing a edge or vertex
Remove unused/rarely used params to const lookup, use StaticScope.

In an effort to eliminate the deopt caused by const access from
Ruby code, I'm working toward making all constant access work
against StaticScope rather than against ThreadContext and the
current DynamicScope (which forces us to push dummy scopes where
we don't really need any). This commit starts pulling out calls to
ThreadContext.getConstant, which requires a DynamicScope to be
present, and also removes some unused or rarely-used arguments
from the const lookup call chain to simplify the transition.
More decoupling of constant lookup from ThreadContext.

* setConstantInCurrent moved to StaticScope
* setConstantInModule moved to RuntimeHelpers
* setConstantInObject moved to RuntimeHelpers
* getConstantDefined moved to StaticScope#isConstantDefined
* A few more ThreadContext#getConstant calls eliminated
Modify compiler to use non-deprecated const lookup methods.

* Const lookup and defined pass in StaticScope
* AbstractScript/RuntimeCache receive StaticScope
* Compiled code uses context.getCurrentStaticScope for now
Decouple compiler and class/module const assignment from TC.

* Compiled setConstant calls work against StaticScope
* Getting the namespace in which to define class/module uses StaticScope
Constant lookup/caching decoupling from ThreadContext for InDy.
Modify scope and block creation to decouple them.

* Single method decodeScope for decoding all types of scopes
* New StaticScope::Type enum to indicate type of scope
* Closure creation receives StaticScope rather than instantiating
Pass parent StaticScope into creation.

This allows us to provide the parent scope without having it
pushed on ThreadContext.
Cache StaticScope for class bodies outside the body execution.

This helps decouple class/module creation from StaticScope init,
allowing us to move closer to getting the current scope from cache
in all cases.
Final modifications to get scopes loading from cache.

* For initial Script execution via __file__, must setRootScope
* Script.load impl will setRootScope
* All other method forms will receive scope index from parent compiler
Tweak cvar logic in compiler to use cached scope.
Fix defined?(@@cvar) to use cached scope and disably dummy scope.

With this commit, scopes that have classes, methods, constants,
and cvars no longer have a requirement that a dummy scope be
pushed. The scope is loaded from the same cache as other values,
and as a result those methods have no implicit cost over the same
code with no scope access.
Indy optimization for constant lookup with cached scopes.
Resolve conflicting getOldName definitions from rebase.
Merge pull request #425 from prathamesh-sonpatki/graph-library-tests

Fixed implicitly creating a vertex if it is absent while removing a edge or vertex
Initial support for Drip, with dripmain.rb for pre-booting.
Add JRUBY_DRIP_WARMUP env for warmup and tweak preboot a bit.