Support for custom expressions in search engine

optional map of expressions can be passed to the client if they exist they are simply converted to a json object and sent to the search engine

expressions are not formatted they rely on the schema in the given BC and as such are simply represented as strings in the framework

Signed-off-by: Robin Smith <robin.smith@clicktravel.com>
Update to the support for expressions

Signed-off-by: Robin Smith <robin.smith@clicktravel.com>
Default static search options for convenience

Signed-off-by: Robin Smith <robin.smith@clicktravel.com>
the word then

Signed-off-by: Robin Smith <robin.smith@clicktravel.com>
Merge pull request #41 from clicktravel-robin/master

Support for custom expressions in search engine