Fix installation error by properly packaging the README.rst

+ .gitignore
Make CSS generator smarter about which fonts to group together

CSS can only cover a limited set of styles: it knows about font weight, and
about the difference between regular and italic.

Anything else, like condensed, for example, will need to be  be put into a
different font family, because there is currently no way to encode it into CSS.

Example output:

@font-face {
    font-family: 'Nimbus Sans L';
    font-style: 'normal';
    font-weight: '400';
    src: url('NimbusSanL-Regu.eot'); /* IE9 Compat Modes */
    src: url('NimbusSanL-Regu.eot?#iefix') format('embedded-opentype'),
         url('NimbusSanL-Regu.woff') format('woff'),
         url('NimbusSanL-Regu.ttf')  format('truetype');
}

@font-face {
    font-family: 'Nimbus Sans L';
    font-style: 'italic';
    font-weight: '400';
    src: url('NimbusSanL-ReguItal.eot'); /* IE9 Compat Modes */
    src: url('NimbusSanL-ReguItal.eot?#iefix') format('embedded-opentype'),
         url('NimbusSanL-ReguItal.woff') format('woff'),
         url('NimbusSanL-ReguItal.ttf')  format('truetype');
}

@font-face {
    font-family: 'Nimbus Sans L Condensed';
    font-style: 'normal';
    font-weight: '400';
    src: url('NimbusSanL-ReguCond.eot'); /* IE9 Compat Modes */
    src: url('NimbusSanL-ReguCond.eot?#iefix') format('embedded-opentype'),
         url('NimbusSanL-ReguCond.woff') format('woff'),
         url('NimbusSanL-ReguCond.ttf')  format('truetype');
}

@font-face {
    font-family: 'Nimbus Sans L Condensed';
    font-style: 'italic';
    font-weight: '400';
    src: url('NimbusSanL-ReguCondItal.eot'); /* IE9 Compat Modes */
    src: url('NimbusSanL-ReguCondItal.eot?#iefix') format('embedded-opentype'),
         url('NimbusSanL-ReguCondItal.woff') format('woff'),
         url('NimbusSanL-ReguCondItal.ttf')  format('truetype');
}