Fix variadic calls with float/double arguments

Problem was due to incorrect way to call C method ffi_prep_cif_var,
where third argument was passed as total number of arguments instead of
fixed number of arguments

This fixes ruby-ffi on the ppc64el architecture, and should be harmless
on other architectures. This was tested at least on amd64 (x86_64) and
ppc64el.

Signed-off-by: Antonio Terceiro <terceiro@debian.org>
Add support for arm64 and mips64el

These are new architectures Debian is being ported to.

Fixes #363
make function calls with enum arguments JustWork

matches behavior of JRuby FFI
make function calls with float arguments JustWork with enums
pass options to rspec call
Add specs for non int enum arguments

not all pass currently
additional specs and a minor fix
Add optional FFI::Type argument to Library#enum and Enum.new

alll tests pass
documentation
add jruby to tests

also gitignore .bundle and vendor
this is largely to cause travis to rerun the tests
re-add EnumTest additions
Add support for the ppc64el architecture

- add types.conf configuration file
- differentiate between powerpc and powerpc64

Signed-off-by: Antonio Terceiro <terceiro@debian.org>
Merge pull request #379 from terceiro/ppc64el

Add support for the ppc64el architecture
Merge pull request #365 from terceiro/debian-ports

Add support for 3 new Debian architectures: arm64, mips64el and ppc64el
Merge pull request #321 from tduehr/typed_enums

Typed enums
fix blocking function spec
Merge pull request #397 from tduehr/fix_test

fix blocking function spec