Support to include theme 2.0

[offtherailz]

Include and support theme 2.0.

After this step, we can imagine to allow inclusion and dynamic switching with proper loaders. see this: geosolutions-it/MapStore2-theme#99

[allyoucanmap]

Some notes:

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css">
<!--<link rel="stylesheet" href="https://rawgit.com/geosolutions-it/MapStore2-theme/master/theme/default/css/css.css">-->
<link rel="stylesheet/less" type="text/css" href="MapStore2-theme/theme/default/theme.less" />
<script src="//cdnjs.cloudflare.com/ajax/libs/less.js/2.7.2/less.min.js"></script>
<link rel="stylesheet" href="MapStore2-theme/theme/default/css/ms2-theme.css">
<link rel="stylesheet" href="MapStore2-theme/theme/default/css/icons.css">

I included the theme2.0 with the above setup with the less CDN to test the variables.less.
I noticed that if i try to change the brand color (e.g. black) it changes only in few styles (e.g. background of icons) the others are still the same color because there are color/background-color in the ms2-theme.css.
In the image are highlighted in red all the color/backgroung color in the ms2-theme.css.

Some icons have a overflow problem, in the image below the eye is clipped the reason could be because the font is outside of the borders

this is the theme2.0 eye font

this is the previous eye font