remove "~YUIDOC_LINE~!" from generated documentation

This happens because YUI does a regex replace to close end of lines with
"~YUIDOC_LINE~!". If you put the description of the parameter on the
next line, you need to have at least one word on the line the parameter
is defined. e.g.:

/**
  @method foo
  @param wait A
    thing I am describing
**/

vs

/**
  @method foo
  @param wait
    A thing I am describing
**/

fixes emberjs/website#376
Merge pull request #2331 from fivetanley/weird-yuidoc-line

remove "~YUIDOC_LINE~!" from generated documentation