absolute submodule urls

* avoid forking all boost submodule repos
redirect submodule urls, line ending normalization

* boost-1.55.0 tag came before conversion to git
* some line ending normalization commits were made in git
* need to cherry-pick these commits to these submodules
* necessary for xpro-1.55.0 branch (off the boost-1.55.0 tag)
line ending normalization cherry-pick commits

* these submodule repos each have a xpro-1.55.0 branch off the boost-1.55.0 tag
* the line-ending normalization commits (from the master branch of each repo) were cherry-picked

boost list discussions
* boost git [Line endings in bootstrap.bat on Windows](http://lists.boost.org/Archives/boost/2013/11/208869.php)
* boost conversion [Isolating the phantom file changes problem](http://lists.boost.org/Archives/boost/2013/11/208936.php)

GitHub Help
* [Dealing with line endings](https://help.github.com/articles/dealing-with-line-endings#platform-all)
* [Re-normalizing a repository](https://help.github.com/articles/dealing-with-line-endings#re-normalizing-a-repository)

To discard the changes that were showing up when switching to the boost-1.55.0 tag,
(where `git checkout -- foo` and `git stash` did nothing) I needed to:
```bash
git rm .gitattributes
git add -A
git reset --hard
```
as described in [a stackoverflow thread](http://stackoverflow.com/questions/11383094/unstaged-changes-left-after-git-reset-hard)