The main problem with building this port with clang was the use of
shared_ptr without the boost namespace which clashes with libc++. This
occurs in numerous places but luckly sed can fix most of them save for
a few files that inconsistently used boost names.
It was also missing an explicit link to libboost_system [1]
PR: ports/176172
Submitted by: Oliver Hartmann
Approved by: Maintainer timeout
Stage support: blanket approval
MFH: 2014Q2
