removed unused codes
Add JNA 3rd party library.
Stub native call ops.
Stub the NativeCall and CPointer REPRs.
Set correct argument signatures for native call ops.
Add JNA to build and runtime JARs.
First implementation of nqp::buildnativecall.
Move constants to enum from static final byte FOO.
Build NativeCallInstance.{arg_types,ret_type} in nqp::buildnativecall.
Basic call handling and converting between NQP and JNA types.

This means that we support int, num, str and cpointer as arguments and return
values, which in turn means that we pass the basic sanity tests in the NQP
test suite.
Run native call tests as part of the standard test target.
Merge branch 'master' into nativecall-jvm
Stub the CArray and CStr REPRs.

We need these to get NativeCall.pm6 to compile.
Stub nqp::nativecallrefresh.

Also needed to get NativeCall.pm6 to compile.
Saner git pull address

The http:// is more likely to work in limited environments, hence it will
work for more people trying to compile with --gen-X
Remove parasithic lookaheads

According to jnthn leftovers from when the LTM wasn't too smart
Copy over the documentation of the radix op from nqp.ops.
Add test for nqpp::radix.
add overview/section headings

Add section headings analagous to jnthn++'s presentation
Add arithmetic opcodes

Slight change to markdown markup to better highlight opcode variants