try setting CC in the environment for clang+bindings builds to get travis to actually use clang for them

Perl bindings (minus travis-ci)

Fix LC_ID_DYLIB for OS X

Wrapping the SHLINKFLAGS in an array rather than as a single string
caused the link flags to be passed to clang double quoted. This cuased
clang to interpret the flags as a string rather than as a flag which
caused the -install_name flag to never be passed to the linker.