Alphabetize JavaScript console snippets

Ordering these snippets alphabetically based on their descriptions makes
it easier to find what you are looking for and to notice any snippets
that may be missing from the list.
Add missing console API methods to JS snippets

This commit adds snippets for the following console API methods that
were missing:

  - console.clear
  - console.dir
  - console.dirxml
  - console.groupCollapsed
  - console.info
  - console.profile
  - console.table

I left out console.debug and console.exception since they are simply
aliases for console.log and console.error.

Information about the console API can be found at:

  https://developers.google.com/chrome-developer-tools/docs/console-api
  https://developer.mozilla.org/en-US/docs/Web/API/console
Improve console.timeStamp snippet

The console.timeStamp method is camelCased, so I made the description
match the contents. Additionally, there was a missing semicolon at the
end of the line that I added.
Add "b" trigger option to JS console snippets

The "b" trigger option will require that the snippet be expanded only if
it is at the "beginning of the line", that is, only whitespace may
precede the tab trigger.

As suggested by @SirVer[1], this commit adds the "b" tab trigger option
to all of the JavaScript console API snippets.

[1]: https://github.com/SirVer/ultisnips/pull/122/files#r8665940
Merge pull request #122 from lencioni/add-snippets

javascript: generell improvements by lencioni.