Add an inline sourcemap to uncompiled builds

This adds an inline sourcemap to concatenated builds (those without `compile` options).  The benefit of an inline sourcemap is that only a single file has to be hosted (as opposed to all ol and Closure Library sources).  The drawback is that the single file is massive.  This bumps the `ol-debug.js` size from 3.4MB (already unwieldy) to 8.9MB.