[Tizen][Runtime] Add default csp support for tizen.

The default CSP policy should be enforced if web app is under
CSP mode without setting any csp rule in config.xml.

BUG = XWALK-1776
Merge pull request #2000 from CooderIan/add_defalut_csp

[Tizen][Runtime] Add default csp support for tizen.
[Runtime] Add collapse white space for widget attr.

According to
http://www.w3.org/TR/widgets/#rule-for-getting-a-single-attribute-value

We need to replace any sequences of space characters with a
single U+0020 SPACE character, then we need to remove any
leading or trailing U+0020 SPACE characters from value.
[Runtime] Add IRI items validate for widget.

According to
http://www.w3.org/TR/widgets/#iri-attribute
http://www.w3.org/TR/widgets/#table-of-elements-and-their-attributes

The id and authorHref are IRI item, and we need validate and trim
white space for they, and if they are illegal they will be empty.
[Runtime] Fix wrong write of variable name on js.

Fix it.