Errors building ceph post c++11 merge

Errors building ceph post c++11 merge

[Joao Eduardo Luis]

To all of those who may be afflicted by various build failures after the
c++11 patches were merged, don't panic just yet.

If you are using ccache to help your builds, try clearing the whole
cache first.

As of right now, this has fixed the following build errors on trusty for
(at least) two developers:


> ./.libs/librados.so: undefined reference to
`__cxa_throw_bad_array_new_length'
> collect2: error: ld returned 1 exit status

and

> /usr/bin/ld: test/librados/ceph_test_rados_api_io-io.o: relocation
R_X86_64_32 against `.rodata' can not be used when making a shared
object; recompile with -fPIC


Hope this email helps someone else avoid wasting a morning on this.

  -Joao