[TASK] Use valid HTML comment delimiters

This changes the comment end delimiter to '---->' (without '!') to avoid
parsing errors due to HTML comment cleanup as done by some extensions
like EXT:sourceopt and to meet the HTML comment syntax as described by
the W3C: http://www.w3.org/TR/html-markup/syntax.html#comments
[BUGFIX] Ensure instanciation of Object- and ConfigurationManagers

Fixes: #198
Merge pull request #202 from NamelessCoder/assetbug

[BUGFIX] Ensure instanciation of Object- and ConfigurationManagers
Merge pull request #203 from tbal/htmlcomments

[TASK] Use valid HTML comment delimiters
[TASK] Use valid HTML comment delimiters (finally)

The previous commit on this (846e418) only removed the '!' char in the
comment end delimiter, but did not actually adjust the comment delimiters
to meet the HTML comment syntax as described by the W3C
(http://www.w3.org/TR/html-markup/syntax.html#comments) as stated in the
commit message.

This commit finally does by adjusting the delimiters to the usual syntax
('<!-- ... -->').
Merge pull request #204 from tbal/htmlcommentsagain

[TASK] Use valid HTML comment delimiters (finally)