wabac.js 2.18.0

What's Changed

adblock support by @ikreymer in #167

optional support for injecting adblock css rules for domain:

• configure with adblockUrl=... in sw init or collection init pointing to Adblock Plus formatted rule files (can be gzipped)
• /mp_/adblock:<domain> returns ad css selectors to hide for domain,
• /mp_/adblock: returns ad css selectors for any domain
• injected into head insert header along with wombat (no changes to wombat)

live proxy testing example with adblock:

• enable adblock per collection by passing in 'adblockUrl' in collection config
• add index-adblock.html to examples/live-proxy/ to test adblock with live proxy
• add fetch-adblock.sh to fetch adblock rules from easylist for testing
• add 'start-live-proxy' script to enable live proxy testing
• rename index.js -> loadwabac.js enable testing on multiple collections

Full Changelog: v2.17.3...v2.18.0