Add support for binary data

[csthomas]

Summary of Changes

Add two new methods:

• $db->quoteBinary() - required by ms sql server (to explicitly cast a value on INSERT query)
• $db->decodeBinary() - required by Postgresql/Pgsql drivers to get the original binary string.

Add a missing class DatabaseSqliteCase in order to load ./Stubs/ddl.sql file and the same ./Stubs/database.xml file as on other drivers.
Previously, phpunit loaded SQL/XML data from the additional package 'Joomla\Test'.

Testing Instructions

Code review.
Unit tests should pass

Documentation Changes Required

To work properly with a binary string, we have to quote it using quoteBinary(). This method replaces the binary string with hexadecimal text wrapped in the specified format depending on the database driver.

When we want to get value of BLOB/VARBINARY then Postgresql/Pgsql database API returns an equivalent of binary string.

Postgresql (>= 9.0) by default returns hexdecimal text or (<9.0) escaped string.
I changed SQL variable buffer_output to always return escaped string and then use pg_unescape_string to get the original binary string.

PgSQL returns a stream instead of string. To get the original binary string we have to use stream_get_contents().

Other databases do not require this additional conversion. For the code to work properly regardless of the database driver, we will use $db->decodeBinary($value).

[mbabker]

The new methods should be added to the interface as well.

[mbabker]

I shouldn't review PRs on mobile. I thought this was targeted to the 2.0 branch, so 889c2f2 should be reverted if it's going to master. My bad.

[csthomas]

OK. No problem.