feature config file for the core.sys.linux tree
deprecate clear
Merge pull request #415 from dawgfoto/DeprecateDestroy

deprecate clear
add core.sys.linux.dlfcn

- core.sys.posix.dlfcn
  - fix linux-MIPS constants
  - deprecate non-POSIX function
add core.sys.linux.link
Merge pull request #406 from dawgfoto/GNULinuxLinkHeader

GNU/linux <link.h> header
druntime implementation for the new ELF registration

- Store information from self-registering libraries. The compiler
  provides ModuleInfos and EH tables.
reference _d_dso_registry for weak-linkage

- because we're linking against archives the linker
  would never read the rt/dso.o object file
Merge pull request #397 from dawgfoto/SharedRuntime_2

druntime implementation for the new ELF registration