standards-compliant URI escaping
optimize and test Utils.escape()

Fixes #159
improve Retry middleware, change to only handle timeouts

Also supercharge it with :max, :interval, and :exceptions options.

Closes #158
fix Retry middleware on 1.8
fix release process from branch other than master

[ci skip]
don't override excon's global connection settings

Update excon's settings on the connection instance, not globally for
all connections (even ones made outside of faraday). Address
deprecation warnings.
set excon timeouts from faraday configuration and handle timeout errors
add ability to set default connection options for all connections
add  ability to pass excon-specific options when initializing the adapter
Disabled failing timeout test.
Fix permissions of Rakefile
Merge pull request #162 from archfear/excon

Bugfixes and additional configuration options for Excon
don't test with Typhoeus v0.4.x

Typhoeus 0.4.0 broke the ability to send PATCH requests with body.

See https://github.com/typhoeus/typhoeus/pull/171#issuecomment-6327082
`script/test` spins up test server, runs test suite
Excon: fix file uploads
raise proper exception for Excon timeout
enable Excon tests on Rubinius
remove Travis & Gemnasium badges from README

Rationale:

 - Who cares if the master branch is failing? Most users should be
   interested in tagged versions only, which we make sure are green.

 - Who cares if gem dependency status is "out of date"? We are using the
   versions of dependencies that work for us in testing.

 - The badges are visually noisy, especially when Markdown is viewed raw.
   Markdown is supposed to be readable.

 - I often view rendered README files for gems while offline and it
   helps if they load no external images.

 - It's time for badges, like/share/retweet buttons, etc. to fade away.
   http://informationarchitects.net/blog/sweep-the-sleaze/
improve Readme
Add Zlib::GzipFile::Error to the list of errors that may be raised by net/http

Closes jnunemaker/twitter#276