feat(directive): ng:switch

[lgalfaso]

Added the ability to handle multiple matches on ng:switch-when and ng:switch-default

Closes #1074

[pkozlowski-opensource]

PR Checklist (Minor Feature)

• Feature improves existing core functionality
• API is compatible with existing Angular apis and relevant standards (if applicable)
• Contributor signed CLA now or in the past (after signing leave a comment here with your real name)
• PR doesn't contain a breaking change
• PR contains unit tests
• PR contains e2e tests (if suitable)
• PR contains documentation update
• PR was tested on ci.angularjs.org for cross-browser compatibility
• PR is rebased against recent master
• PR is squashed into one commit per logical change
• All changes requested in review have been implemented
• PR's commit message is descriptive and allows us to autogenerate release notes (required commit message format)

[IgorMinar]

is the main motivation behind this PR ability to switch over groups of table rows or list items (where it's impossible to create artificial divs to group nodes)? If so, the unit tests should reflect that.

[lgalfaso]

you are right, the motivation is that sometimes it is not possible to add artificial elements

[lgalfaso]

Do not want to be a pain in the neck here, but would it be possible to know if there is anything else needed for this patch to be merged?

[IgorMinar]

I made a few cosmetic changes and landed the change as 0af1720

thanks for the contribution!