Do not crash when a repo has a detached HEAD

Instead, we select a default branch - master by default, but the default
branch can be configured using config.ini.

Note that if the default branch does not exist in a repo, that should
not cause any issues.

Also adds phpunit to composer.json's require-dev section.
Add packages for making build to composer.json's require-dev

Not all of the packages for doing a build are available via composer,
but many of them are. This reduces the amount of work it takes to set up
an environment to do a full build.
Default require-dev packages to most recent minor version
Revert changes to composer.json and composer.lock

Note that this commit depends on a pull request for gitter, and is
therefore in an untestable state after reverting composer.json.
Its predecessor should be testable, however.
Revert composer.lock

since I updated a bunch of entries that did not need to be updated.
Update composer.lock for dev dependencies
Fix raw blob view

A previous change of mine had broken it.

Also rename a route parameter in CommitController for consistency with
other route params.
Merge pull request #263 from NateEag/handle-no-active-branch

Do not crash when a repo has a detached HEAD
Merge pull request #264 from NateEag/add-build-packages

Add packages for making build to composer.json's require-dev
Merge pull request #266 from NateEag/fix-raw-blob-view

Fix raw blob view
Init builder ...
RPM e Debian build core + README
README + tools
Edit readme
rename
Fix ...
Fix ...
Fix ...
Merge pull request #268 from bggo/master

Initial package builder
Use absolute URLs in RSS feeds