Add compiler:c++11-lang to USES to fix build on GCC-based architectures:

/usr/local/lib/libgraphite2.so.3: undefined reference to `__cxa_throw_bad_array_new_length@CXXABI_1.3.8'

While here, pet portlint and alpha sort some USE* variables.

Approved by: portmgr (tier-2 blanket)