JSLint issues to be fixed

[Olek Nowodziński]

(major=db6ffc3) oleq@pc ~/ck/ckeditor-dev> dev/jslint/linter 
~/ck/ckeditor-dev/dev/jslint ~/ck/ckeditor-dev
/home/oleq/ck/ckeditor-dev/core/filter.js(208): SyntaxError: invalid quantifier {
					else if ( el.type == CKEDITOR.NODE_COMMENT && el.value.match( /^{cke_protected}(?!{C})/ ) ) {
......................................................................................................^

/home/oleq/ck/ckeditor-dev/core/htmldataprocessor.js(158): lint warning: missing semicolon
			if ( !context && context !== null )
........................^

/home/oleq/ck/ckeditor-dev/core/htmlparser/comment.js(62): warning: anonymous function does not always return a value
	},
........^

/home/oleq/ck/ckeditor-dev/core/htmlparser/element.js(199): warning: anonymous function does not always return a value
					return;
..............................................^

/home/oleq/ck/ckeditor-dev/core/htmlparser/element.js(206): warning: anonymous function does not always return a value
					return false;
....................................................^

/home/oleq/ck/ckeditor-dev/core/htmlparser/element.js(243): warning: anonymous function does not always return a value
		},
................^

/home/oleq/ck/ckeditor-dev/plugins/preview/plugin.js(98): warning: anonymous function does not always return a value
		}
................^

/home/oleq/ck/ckeditor-dev/plugins/stylescombo/plugin.js(180): lint warning: undeclared identifier: loadStylesSet
/home/oleq/ck/ckeditor-dev/plugins/format/plugin.js(35): lint warning: comparisons against null, 0, true, false, or an empty string allowing implicit type conversion (use === or !==)
		if ( stylesCount == 0 )
......................................^


1 error(s), 8 warning(s)
~/ck/ckeditor-dev

Seek and destroy.

[Olek Nowodziński]

Created branch ​t/10097@cksource with JSLint fixes.

Note: needs careful review even though tests say OK. Modified regular expressions and returned values of filter sub-methods.

[Piotrek Koszuliński]

I pushed one more tiny fix. The rest is ok.

[Olek Nowodziński]

Changes merged into major in ​git:69dcd98f4b.