Fix formatting for couple of docs in the compiler

Source code on scaladoc for the virtual pattern matcher was not being
correctly identified as such. Also, I had to use an html code tag instead
of backticks when referring to the __match identifier, otherwise the
double underscore would be treated as start-of-underline wiki markup.
Merge pull request #2526 from dcsobral/doc/patMat

Fix formatting for couple of scaladocs in the compiler
Merge pull request #2527 from soc/SI-7476

SI-7476 Add documentation to GenericTraversableTemplate
SI-7469 Remove @deprecated scala.util.logging