Improve script URL ecoding

added some magic to get scripts to efficiently encoded into the URL.
We're using pako to compress the script, but this outputs to a 8bit
array. Stringifying this array adds a lot of overhead, because "125"
has three characters in it.
Instead we're using the character codes to turn these a bit numbers
into single characters base64 is used as well because not all of the
characters are allowed in a url (and b64 is better than
encodeURIComponent).

app/.gitignore

@@ -0,0 +1 @@
+dist