Change debugging contract for oegdb. Enclaves and hosts built prior to this
release cannot be debugged with this version of oegdb and vice versa.
Update Intel DCAP library dependencies to 1.3.
Update Intel PSW dependencies to 2.7 on Linux and 2.5 on Windows.
SGX1 configurations always take build dependency on Intel SGX enclave common library.
Update LLVM libcxx to version 8.0.0.
Update mbedTLS to version 2.16.2.
The mbedTLS libraries used in Open Enclave will no longer be compiled with the
following config.h options in the next (v0.8) release:
MBEDTLS_TLS_DEFAULT_ALLOW_SHA1_IN_KEY_EXCHANGE: Considerable advances
have been made in breaking SHA1 since our original review and we would
like to be more prescriptive in recommending the use of SHA256.
MBEDTLS_KEY_EXCHANGE_RSA_ENABLED: This option provides no perfect
forward secrecy and is generally becoming less popular as this is
recognized. The ECDHE variants are also more performant.