JDBC 4.5 support: add support for selectively disabling escape / parameter marker processing (JDBC escape {\ ... \})

[mrotteveel]

JDBC 4.5 introduces a JDBC escape to selectively disable escaping and parameter marker processing with the escape {\ ... \} (e.g. in a Java literal "... {\\ ... \\} ..."). For Jaybird we don't need to disable parameter marker processing, as parameter processing is done by the server (also, Firebird currently has no syntax with ? meaning anything other than parameters anyway).

We'll need to adjust JDBC escape processing to handle the {\ ... \} appropriately (i.e. unescape escaped \, and not do nested escape processing).

[mrotteveel]

The specification is not clear on what should happen if a bare end marker (\}) occurs in a SQL string literal, delimited identifier or comment: should it end escape processing, or should it throw an exception? I've sent a mail to Lance Andersen and Douglas Surber asking for clarification.