package.json license array format is deprecated and problematic for tool usage

[bbarry]

package.json currently lists the projects licenses in an array which is deprecated by npmjs:

Some old packages used license objects or a “licenses” property containing an array of license objects:
...

Those styles are now deprecated. Instead, use SPDX expressions

Projects like https://github.com/microsoft/license-checker-webpack-plugin pick up the license here as either MIT or SIL (generating an incorrect SPDX expression of "(MIT OR OFL-1.1)").

The following changes should be made to this repository:

1. remove package.json/licenses member
2. add package.json/license member with value "(MIT AND OFL-1.1)"
3. rename ICON-LICENSE as LICENSE.MIT
4. rename FONT-LICENSE as LICENSE.OFL-1.1