This requires that things use #include <sysprof.h> now instead
of individual includes. A few cases are still allowed in the
libsysprof-capture library to make copy/paste embedding easier.
As we gain in usage, we need to be more careful about using a prefix
that will not collide with other symbols. So version 3 of our ABI will
change to using Sysprof/SYSPROF/sysprof as the various prefixes.
The soname/api version bump will happen later on this branch so that
things are easier to test up until then.
