Added 'bool' support to user editable parameters
The parameter will be displayed as checkbox in the generated form.
For default values of type other than boolean an error will be displayed.
In the user script the value can be used as boolean.

example:
{ name: 'check', caption: 'awesome?', type: 'bool', default: true }
Added 'longtext' support to user editable parameters
The parameter will be displayed as textarea in the generated form.

example:
{ name: 'multilineText', caption: 'Long text:', type: 'longtext', default: "long\ntext\nis\nlong" }
Merge branch 'additional_types' into gh-pages