Merge pull request #117 from dreipunktnull/master

[DOC] Fix 'typo' in argument description
[BUGFIX] Reverse order __toString / Domain object id fetch

Fixes: #109
[BUGFIX] Disable cache if positive in Once and Security ViewHelpers

Fixes: #116

This change overrides the `renderThenChild` method in the abstract classes for Once and Security scope ViewHelpers. When a positive condition is encountered, the output should be considered specific to the current visitor only - achieved by simply preventing caching of the page being rendered.
[FEATURE] Asset DNS Prefetch ViewHelper

This is a special type of Asset which only generates a `<link rel="dns-prefetch" href="…" />` tag for each domain given in the `domains´ attribute (mixed, supports CSV and Iterators).
Merge pull request #118 from NamelessCoder/issue/109

[BUGFIX] Reverse order __toString / Domain object id fetch
Merge pull request #119 from NamelessCoder/issue/116

[BUGFIX] Disable cache if positive in Once and Security ViewHelpers
Merge pull request #120 from NamelessCoder/assetdnsprefetch

[FEATURE] Asset DNS Prefetch ViewHelper