Added changelog entry for pull #1960

Cleanup pod directory when download fails (probably due to a network error)

Conflicts:
	CHANGELOG.md

Fixes #1950.

Merge branch 'command-list-added-pod-versions' of https://github.com/z00b/CocoaPods into z00b-command-list-added-pod-versions

See https://travis-ci.org/CocoaPods/CocoaPods/jobs/21842661

Merge branch 'cleanup-pod-dir-on-failed-download' of https://github.com/alexrothenberg/CocoaPods into alexrothenberg-cleanup-pod-dir-on-failed-download

As requested in original PR (#1617).

Also remove some extraneous whitespace that crept in.

Use "gem install" instead of "gem update" in notice, as it is recommended

Fixes #1482

Changelog for 1721

Update changelog to add Master section

Mainly for sanity reasons during the bug bash

Add advice for UTF-8 issue on Travis CI

when new version detected, show command to update

* master: (88 commits)
  [Gemspec] Switch back to cocoapods-try in favour of the release fix
  [Gemfile] Add version requirements to rake for Ruby 1.8.7
  [Integration] Update tests
  [Gemspec] Bump Xcodeproj version
  [Gemspec] Bump CLAide version
  [Gemspec] Bump cocoapods-downloader version
  Join the two description paragraphs of
  Required parameters should not contain square braces
  Add different wording for `lib create` command description
  Name is not optional -> no square braces
  Add Changelog note for `pod lib create` template URL
  Add note for `pod lib create` and optional template URL
  Add possibility to specify a template URL
  Convert indention into spaces instead of tabs
  Ensure file descriptors are closed
  [Search] Web search should escape queries
  [Search] Don't validate for valid regex on web searchs
  pod_target_installer: Remove 6-month-old comment.
  validator.rb: Conform to 2-space indentation.
  validator.rb: Print xcodebuild command on -v.
  ...

Conflicts:
	CHANGELOG.md

[BUILD] Update Rakefile with procedures to check presence of bzr and hg.