TlsClient introduced a non-blocking read which is required to read protocol messages that are linefeed-terminated rather than a known size. However, in many cases the expected number of bytes is known in advance so in that case it is more efficient to have tlsClientRead() block until all the bytes are read.
Add block parameter to all read functions and use it when a blocking read is required. For most read functions this is a noop, i.e. if the read function never blocks then it can ignore the parameter.
In passing, set the log level of storageNew*() functions to debug to expose more high-level I/O operations.
* Allow more than one test to provide coverage for the same module.
* Add option to disable valgrind.
* Add option to disabled coverage.
* Add option to disable debug build.
* Add option to disable compiler optimization.
* Add --dev-test mode.
* More optimized container suite that greatly improves build time.
* Added static Debian packages for Devel::Cover to reduce build time.
* Add deprecated state for containers. Deprecated containers may only be used to build packages.
* Remove Debian 8 from CI because it does not provide additional coverage over Ubuntu 14.04 and Ubuntu 16.04.
