2.10.4-RC1
add deb/rpm to MakeDownloadPage
Use MakeReleaseNotes.genPR to generate scala/scala-lang PR.

It also doesn't actually download the files anymore,
just parses the Content-Length part of the header (asynchronously).

For example:
```
sbt -Dfile.encoding=UTF-8 console
scala> MakeReleaseNotes.genPR("2.10.3", "2.10.4-RC1", "2013/12/20")
```

The output is copy/pasteable in bash to create your scala/scala-lang PR.
Merge pull request #39 from adriaanm/2.10.x

Encapsulate release notes gen, 2.10.4-RC1 data
2.11.0-M8 announcement

Markdown generated with:

```
sbt -Dfile.encoding=UTF-8 console
scala> MakeReleaseNotes.genPR("2.11.0-M7", "2.11.0-M8", "2014/01/28")
```

sanity checked (after sudo gem install maruku): `maruku --html 2014-01-28-release-notes-2.11.0-M8.md`
Merge pull request #41 from adriaanm/2.11.0-M8

2.11.0 m8