IE8 Password field fix

Hello, This PR reintroduces support for password fields in IE8.

@rudasn originally added support in PR https://github.com/jrief/angular-shims-placeholder/commit/c46e13726dd8a0b7b3a55ade822b662207479e78

Unfortunately, his PR merged the code into /dist/angular-shims.placeholder.js instead of /lib/angular-placeholder.js, so it got overwritten when rebuilt dist files were added in PR https://github.com/jrief/angular-shims-placeholder/commit/f05c0d8b805a0927a861e27777a1f628b41cff79

The original code also didn't fully work in IE8, and was dependent on jQuery. I resolved the functionality issues and reimplemented the jQuery methods in pure JS.

I also updated the karma tests related to the password field, and incremented the project version number.

I will be submitting an additional PR incoming that resolves some environment issues I ran into while testing.