"bare" tag reopening

[namuol]

The ability to re-open tags at their root level so we can do this:

/**
@Something
  @number 42
*/

// Later...

/**
@Something:
  @number 43
  @number 44
  @number 45
*/

...instead of this:

/**
@Something
  @number 42
*/

// Later...

/**
@Something:number 43
@Something:number 44
@Something:number 45
*/