Fixed regular expression for removing paste_data_images

The existing regex only picked up images where the src attribute immediately followed the tag opening. However, you could have an image tag like <img alt="something" src="data:image...">.
Fixed bug where some comments would be parsed as HTML by the SaxParser.
Added new allow_script_urls option and removed script and style from the default elements list.
Fixed broken performance.html test.
Proposed fix for bug #6410
Merge pull request #255 from jashua212/bug_6410

Proposed fix for bug #6410
Fixed a few issues with the fix for #6410
Add the 'mce-contextmenu' class to the contextmenu so that css can target this menu separately.
Fixed missing text color in default skin
Move var in fix for #6410
Merge pull request #258 from jashua212/bug_6410

Move var in fix for #6410
Merge pull request #256 from tractionsoftware/contextmenu-class

Add the 'mce-contextmenu' class to the contextmenu
Merge pull request #257 from black-silence/master

Fixed missing text color in default skin
Merge branch 'patch-5' of github.com:danransom/tinymce into danransom-patch-5
Added tests for paste_data_images and fixed some code formatting.
Fixed some UI bugs and broken unit tests.
Fixed various unit tests.
Fixed bug where setContent would move focus into the editor even though it wasn't active.
Fixed so source editor moves focus to editor after setting new contents.
Fixed bug where IE 11 would sometimes throw an "Invalid function" error when calling setActive on the body element.