Support for ::input-placeholder

From “Change an input’s HTML5 placeholder color with CSS”:

::-webkit-input-placeholder { /* WebKit browsers */
    color:    #999;
}
:-moz-placeholder { /* Mozilla Firefox 4 to 18 */
    color:    #999;
}
::-moz-placeholder { /* Mozilla Firefox 19+ */
    color:    #999;
}
:-ms-input-placeholder { /* Internet Explorer 10+ */
    color:    #999;
}

I tried different variations (::input-placeholder, ::placeholder) but seems like it doesn’t supports by autoprefixer.

Thanks.

[ai]

@thomaswelton ouh, if you interesting I can explain much more deeper 😄.

When Autoprefixer adds new prefix, it must check maybe selector is already prefixed. So, when you run Autoprefixer twice (for example, guys in text editor plugins like to run Autoprefixer on already autoprefixed sources) it will not double its prefixes.

So selector prefixer merge unprefixed selector and all prefixed nearby into one block. And then check is block already contains some prefixes.

Without comment, Autoprefixer combine your and Bootstrap styles into one block (because them was near and there is no unprefixed selector in Bootstrap to separate blocks).

[ai]

OK, I next release I will support only ::placeholder, but if some users will complain, I add anothers unprefixed versions.