Added support for ambiguous ampersands

Thanks to @christopherdengler for highlighting the issue here: #5

Fix for `Tag.removeAttr` clearing the cached `_head` value

Thanks to @ba1uev for reporting this issue (#4).

Fix for `String.split` and new `String.join` class method

1.0.5

Bumped version number

Fix for IE edge issue

A description of the issue can be found here: GetmeUK/ContentTools#258 (comment)

Added `require` support for use with browserify

1.0.3

Added exports to module to support for require with browserify.

Added NPM main package value

1.0.2

Added main value to package.json

Added NPM documentation

1.0.1

Added library to NPM

Initial release

Initial release of the HTMLString library.