With libcurl, HttpFetcher now supports timeout and https.
Two additional changes:
1. Remove happyhttp which is no longer needed;
2. Add README.packager for curl
Bug: 13658515
Bug: 14301830
Change-Id: I13c2835e7feca9abf36e5bb8f7bc35a7db9ec94c
Latest rev of happyhttp fixes the bugs so patches are no longer needed.
Also removes http_fetcher_unittest from the build as it performs real
http requests to an external server.