Replace `colors` with `chalk`

colors.js has serious deficiencies like extending String.prototype which can cause all kinds of problems. Two modules using colors.js can conflict with each others, and it infects imported child modules. It's also better to explicit.

[chalk](https://github.com/sindresorhus/chalk)
Close GH-732: Use https:// protocol instead of git:// when a proxy is set.
Fixed a grammar error
Merge pull request #742 from wilkinson/master

Fixed a grammar error
Merge pull request #741 from bower/replace-colors

Replace `colors` with `chalk`
Update change log.
Bump version.
Fix chalk usage on the info command.
Simplify 9c4b30b65c14fe21e6e136d581ddbda95f2d7c72
Close GH-747: Do not use --depth=1 if the server does not support it, fixes #744.
Add missing test.
Update change log.
Bump version.
Add meaningful error when executing bower link on windows when user is not elevated.

#472
Close GH-726: Add relative option to the list command, closes #714..
Normalise windows paths, closes #279.
Fix typo.
Fix host not correctly being set.
Try junctions on windows before erroring out.
Close GH-760: Info command now shows the latest version package meta always, fixes #759.