Allow field default for site plugins.

Use default values for items added via site plugins when plugin doesn't
provide a value.
Move default field values into own function.
Merge pull request #18 from Denney/site-plugin-defaults

Allow use of field defaults in site plugins.
Merge pull request #15 from Denney/parent-item-visibility

Make parent item information visible.
support a jsonrpc class returning FALSE, as apposed to NULL which means no data
support a jsonrpc class returning FALSE, as apposed to NULL which means no data
Merge branch 'master' of github.com:pellcorp/opendb
disable parent item listing due to issue #19
Add PhpStorm project files to ignore list.
Merge branch 'attribute-permissions'
Merge branch 'master' of https://github.com/Denney/opendb