Import net/unbound package from Subversion

This is an import of the net/unbound package from Subversion
revision 40658 (May 2, 2014). The only change is the addition of
PKG_LICENSE, PKG_LICENSE_FILE and PKG_MAINTAINER to Makefile.
Unbound 1.4.22 is the current upstream release.

Signed-off-by: Michael Hanselmann <public@hansmi.ch>
Fix a typo in CONTRIBUTING.md text

Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>
Merge pull request #218 from luizluca/fix-Contributing

Fix a typo in CONTRIBUTING.md text
Merge pull request #216 from hansmi/master

Import net/unbound package from Subversion
Merge pull request #217 from luizluca/trunk/luizluca

Migrate ruby from oldpackages to github and update
ruby: Fix build dependency of gmp/host

libgmp.so is needed for miniruby, that is compiled in host.
Using PKG_BUILD_DEPENDS=gmp/host eventually compiled gmp/host
before ruby/host. However, when this did not happened, build
failed. Using HOST_BUILD_DEPENDS=gmp/host seems to be the
correct way to require it.

Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>