Merge pull request #26 from keithj/devel

Added json-metalist program
Merge pull request #27 from keithj/devel

Updated README
Added ability to define AVU queries in JSON

Updated configure.ac for newer autoconf

Require autoconf 2.68
Merge pull request #29 from keithj/devel

Free memory allocated when the client unpacks structs from the server
Merge pull request #30 from keithj/json_query

Added ability to define AVU queries in JSON
Merge pull request #31 from wtsi-npg/json_query

Json query