Previously, error strings were kept in arrays for each subdirectory and
err.c would iterate over them all and insert them at init time to a hash
table.

This means that, even if you have a shared library and lots of processes
using that, each process has ~30KB of private memory from building that
hash table.

This this change, all the error strings are built into a sorted list and
are thus static data. This means that processes can share the error
information and it actually saves binary space because of all the
pointer overhead in the old scheme. Also it saves the time taken
building the hash table at startup.

This removes support for externally-supplied error string data.

Change-Id: Ifca04f335c673a048e1a3e76ff2b69c7264635be

find -name CMakeLists.txt -type f | xargs sed -e 's/\t/  /g' -i

Change-Id: I01636b1849c00ba918f48828252492d99b0403ac

See https://tools.ietf.org/html/rfc5869.

Change-Id: I6d012d8c38806df80aa44350d3a86eaff499ac05
Reviewed-on: https://boringssl-review.googlesource.com/2533
Reviewed-by: Adam Langley <agl@google.com>