TODO:
- update manual
  - document new dynports
  - check signature format markup (.dyncall)

- updates from dyncall (compare svn 1284 -> 1381)
- name mangling R <-> C ... exchange the first '_' in C -> '.' in R.
- feature: support for function pointers arguments,
    if R closure is passed, auto wrap function a callback object 
    the callback object is appended in a global list 
- bugfix for using callconv prefixes via .dyncall and not .dyncall.*.
  using a different callvm for .dyncall that may be setup via prefixes and
  resets to default always.
- test R build on solaris and sparc(64).
- document win32 expat binary installation
- callbacks should fail with "not yet implemented" on unsupported platforms
- use raw vectors for 1-to-1 bit encoding of values e.g. raw(8) for (u)int64 values
- handling of Csingle attribute on double vectors
- character encoding support, R supports UTF-8.
- Fortran calling conventions
- attr("struct") -> attr("CType")
- parseStructInfos -> cstruct
- parseUnionInfos -> cunion
- .dyncall typed pointer
- as.struct -> as.ctype
- new.struct -> cdata
- new.callback -> cfunction
- planed dynports:glut, curl, openal    

BUGS:
- OpenBSD 4.8/amd64: SDL failed due to pthread.
  R version on OpenBSD does not provide a shared R library, thus
  the symbols are not resolvable.
  Additional Test for resolving self:
  While .dynsym(as.extptr(NULL), "R_ShowMessage") works on Mac OS X, it fails on OpenBSD.
- demo(ttf) failed on Mac OS X 10.6